welcome to our viewers on pbs in america and around the globe. the united nations has described the war in ukraine as a "horror story of violations against civilians", and says there's growing evidence war crimes may have been committed. on saturday it will again be attempted to establish humanitarian corridors out of the besieged southern port city of mariupol, which russian forces have been trying to fully capture for several weeks. our correspondent catherine byaru hanga is in southern ukraine. a warning — her report contains some images viewers may find upsetting. haunting, apocalyptic scenes in mariupol. rapid explosions russia has bombarded this city into near submission. once home to about 500,000 people, thousands are believed to have been killed. emergency workers from russia are filmed here, retrieving the dead. moscow has repeatedly denied that its troops are responsible for the mass killings of civilians in ukraine, but mariupol�*s mayor says some of the worst war crimes have been committed there. translation: they | killed 20,000 people. they did it on purpose. this is what i think. they intentionally prevented people from leaving mariupol. they set this genocide up by closing the city down and using land artillery and air strikes first, and then the warships that arrived later. russian forces have been accused of hiding civilian bodies in mass graves. these satellite images show them appearing over the course of a month. the civilians have been buried in the village of manhush, outside mariupol, the southern city which has been besieged and encircled by russian forces for weeks. the last ukrainian troops in the city are holed up inside the azovstal steelworks, on mariupol�*s coast. 1,000 civilians are still said to be in this sprawling industrial complex. on this missing persons wall, most of the faces and names that you can see are people from mariupol, and now, with the ongoing blockade and with communications cut off, it's almost a miracle for people to get out. these three women escaped mariupol together on thursday — just a handful of people who made it through with a humanitarian convoy. a friendship born out of the horrors of this war. translation: people are risking their lives under fire. _ they have to because there is no running water, gas or electricity. there is a mosque in the prymorskyi district with a well nearby. a lot of people got killed there. they got caught up in shelling. they were just looking for water in the city. but they are safe now, and able to rebuild their lives in new cities and countries. catherine byaruhanga, bbc news, zaporizhzhia. the ukrainian deputy prime minister has told the bbc only the united nations can save the lives of tens of thousands of people stuck in the besieged city of mariupol. let's get more on the latest in ukraine. i'm joined by our news reporter azadeh moshiri. let's start with mariupol and those evacuations. more promises that there could be a corridor of safety, but the question is will it happen? mil question is will it happen? all we know question is will it happen? fill we know right now as ukraine is working on one saturday, about early morning ukraine time, but as you say, they have been so many attempts in the past, and a lot of the time they have failed. it is so difficult for aid agencies to get to mariupol, which requires getting through russian checkpoints, getting through the selling, the situation and so compared about a lot of the time mariupol residents and up fleeing on their own without the protection and help of these aid agencies. this is partly why the deputy prime minister of ukraine, iryna vereshchuk, has told the bbc that the un must intervene themselves when it comes to these corridors. that they are these corridors. that they are the only organisation that has the only organisation that has the strength and capacity to ensure they can work, and that secretary general antonio guterres needs to get involved and intervene immediately to save some of the 100,000 people currently trapped in mariupol today. she also had some criticism, saying so far all the un has done is watch these events happen. the the un has done is watch these events happen.— the un has done is watch these events happen. the un does seem to be reacting _ events happen. the un does seem to be reacting to _ events happen. the un does seem to be reacting to that _ to be reacting to that criticism, we saw announcements made earlier?— made earlier? yes, now we note the secretary — made earlier? yes, now we note the secretary general _ made earlier? yes, now we note the secretary general will - made earlier? yes, now we note the secretary general will be - the secretary general will be visiting moscow next week on tuesday. the plan is apparently to meet with the foreign minister sergei lavrov for a working lunch. he is also going to be received by president putin, whatever that means he will have time for a substantive discussion, we don't know. but he did tweet earlier, discussing the goals of this meeting. he said "we need urgent steps to save lives and end the human suffering, and end the human suffering, and bring about peace in ukraine". he also said later on he will meet with president zelensky in kyiv, and he will also be taking that opportunity to meet with aid agencies on the ground so that they can scale up their humanitarian response, because the un has warned that so far they have had tremendous barriers in delivering aid like food and water, things that, essential needs ukrainian tab on the ground right now. we needs ukrainian tab on the ground right now.- needs ukrainian tab on the ground right now. we have heard somethin: ground right now. we have heard something from _ ground right now. we have heard something from russia, - ground right now. we have heard something from russia, another| something from russia, another admission from them regarding the sinking of the ship, the moskva?— the sinking of the ship, the moskva? , ., , moskva? they said there has been one _ moskva? they said there has been one death, _ moskva? they said there has been one death, 27 - moskva? they said there has been one death, 27 are - moskva? they said there has i been one death, 27 are missing and almost 4000 were rescued. -- 1400 and almost 4000 were rescued. —— 1400 were rescued. it is a significant admission from russia, which has not admitted to any casualties so far. as you say moskva was the flagship of the black sea fleet, its sinking was seen as a significant moment in the war. ukraine says it was sunk by its missiles but russia is insisting it was from a fire on board. that hasn't stopped ukraine from claiming the ship is an item of underwater cultural significance. thank ou for cultural significance. thank you for that _ cultural significance. thank you for that update. - campaigning has ended in france ahead of what's expected to be a close run—off between president emmanuel macron and his far—right rival marine le pen on sunday. opinion polls suggest emmanuel macron still has the upper hand, but his challenger could perform better than she did when the pair went head—to—head in 2017. our paris correspondent lucy williamson reports. it's a bit late for tips on how to learn to punch on his opponent. after five divisive years in power, what emmanuel macron needs is to persuade voters who'd quite like to punch him to give him their vote instead. florentine and chloe are both teachers here in the suburbs of paris. they voted for mr macron last time. now, they've come to give him a hard time. le pen isjust...huge disaster, but macron is still a disaster, i think, for school and service—public, ah, for public services in france. he's killing that, step—by—step. florentine says she'll abstain on sunday rather than vote for macron again. i'm still hesitating. i think if i do it, i might really get sick just after. he's a good talker, he knows how to try to seduce people, but we're not stupid. chloe gets close enough to shout her question on teacher's pay. "do you think teachers are lazy?", she asks. through the scrum, macron grips her hand, and locks in her vote. translation: he gripped my hand and said, "we're going to do - "something about that, i promise." so, i will vote for him, but i want something in return. truck horn honks cheering there's a real choice on sunday about where france is heading. marine le pen is promising huge tax cuts and to "take back control". emmanuel macron wants a global nation, set on economic reform. divisions here are deepening with every election cycle and voters are now split between two radically different views of the world — with one candidate presenting herself as the spokeswoman of the people, and the other saying he's protecting france from her. dylan says he voted far—left in the first round of this election. on sunday, he's voting far—right. translation: it's not that i like the idea of voting - for marine le pen, but we have to choose between the two, and when you're choosing between cholera and the plague, you choose the lesser of two evils. crowd chanting at herfinal rally, here in arras, marine le pen said voters should choose her to block mr macron. both say the other is dangerous. both spark loyalty in their own fans and loathing in those of their rival. but most voters belong to neither camp, and in this battle over france's future, they're being asked to choose a side. lucy williamson, bbc news, paris. voting takes place on sunday in france, and whether you're watching in the uk or around the world, we will have a special programme bringing you the result, starting at 1730 gmt. join us for that, as france decides. in the us, a gunman who opened fire in an upmarket district of washington, dc has taken his own life. four people were wounded in the incident. none of the injuries are said to be life—threatening. police had named the 23—year—old suspect as raymond spencer. the motive for the attack is not yet known. guns are now the leading cause of death for us children and teenagers, according to new research. data from the centers for disease control and prevention shows that over 4,300 young americans died of firearm—related injuries in 2020, overtaking drug overdoses and car accidents. while suicides contributed to the toll, the data shows that homicides form the majority of gun—related deaths. more than 390 million guns are owned by us civilians. a man has been declared an official suspect in the disappearance of madeleine mccann nearly 15 years ago. she went missing during a family holiday in praia da luz in portugal in may 2007, shortly before her fourth birthday. her parents say they welcome today's development, and that they haven't given up hope madeleine may still be alive. our correspondentjon kay has more from praia da luz. her face and name are known around the world, but what happened to madeleine remains a mystery. it was on 3 may 2007 that she vanished from the mccanns�* holiday apartment in praia da luz — the moment her family's lives changed forever. please give our little girl back. overnight, portuguese prosecutors announced that they'd declared a new "arguido", or formal suspect in the case. it's understood to be this man, christian brueckner. the 45—year—old is currently in prison in germany for rape and drugs offences. he's known to have been living in portugal around the time madeleine disappeared, and german investigators say mobile phone records place him in praia da luz. but he has denied any involvement in the mccann case and has not been charged. you know, you have proximity, you have opportunity and you have a profile, with regards to an offender that absolutely fits in the way that no others have. the last decade and a half have seen many potential breakthroughs come and go. madeleine disappeared from her family's apartment while her parents were dining at a restaurant in the complex, and in the early days of the investigation, the portuguese authorities made kate and gerry mccann official suspects, but that status was later withdrawn. injuly 2013, the uk's metropolitan police reviewed the case, saying they had new witnesses and new evidence and they searched areas close to where madeleine was last seen. it was injune 2020 that german police said they'd identified a prisoner as a suspect. and the timing of christian brueckner now being made an arguido appears significant — next month, it will be 15 years since madeleine was reported missing, and under portuguese law, it's not possible for someone to be given arguido status after 15 years. but the authorities here say the move was not driven by timing, but by what they call "strong indications" of the practice of a crime. john kay there. the uk and india have signed a new defence partnership. the agreement was made as borisjohnson continues his visit to india, where he's been meeting his counterpart narendra modi. the bbc�*s ben wright sent this report from delhi. the sun shone, the soldiers saluted and the ceremony never flagged. it was the red carpet treatment for boris johnson, who was here for talks with his indian counterpart, narendra modi. after yesterday's torrid day of political turmoil at home, mrjohnson seemed pleased to bask in the welcome. a joyful reception, i wouldn't get that necessarily anywhere in england. marching band plays this is when the visit got down to business. it's 75 years since india gained independence from britain, and both countries say a free trade deal can be signed this year to mark the moment. next week, we're telling our negotiators, get it done by diwali in october. they had a long discussion about ukraine. india has held a neutral position on russia's invasion, and borisjohnson did not come here to jab or pressure, but mr modi did call for peace. translation: we emphasised on an immediate ceasefire - in ukraine, and on the use of dialogue and diplomacy for resolving issues. while borisjohnson later confirmed the uk intended to deepen its military commitment to the crisis. so, we're looking at sending tanks to poland. that's to allow warsaw to send its tanks to ukraine, and the prime minister also said british diplomats would soon be returning to the capital. i can announce today that we will very shortly, next week, reopen our embassy in ukraine's capital city. it's been a difficult couple of days for the prime minister, who's now facing an inquiry by mps into whether he misled parliament. you said there'll be a free trade agreement with india by diwali, but considering the number of party investigations going on back home, are you absolutely sure you'll still be prime minister then? ok, the second answer is yes, but... all trade agreements are tricky, ben, to get to your point about trade, and there will be tough asks of both sides, but i'm sure we can do it. boris johnson bristles at any mention of parties and the political problems he faces back at westminster. he is clearly irritated that it's taken the focus away from his efforts to deepen britain's ties with this surging economy. but it's where the party saga goes next that could determine boris johnson's future, as he returns to domestic political strife. ben wright, bbc news, delhi. florida's governor has signed a law to prevent disney from acting as a local government and its theme park. it came after disney criticised the ban on teaching about sexuality in schools. the special status allow them to collect taxes and guaranteed public services like rubbish collection and water treatment over an area near disney world. the fugitive businessman, carlos ghosn — who once ran the car—making giant nissan — has told the bbc he would be happy to stand trial on charges of financial wrongdoing, in order to clear his name. mr ghosn, who fled japan while awaiting trial, is now the subject of an international arrest warrant issued by investigators in france. here's our business correspondent, theo leggett. he was the high—flying company boss who came crashing to earth. he once ruled over a car—making empire that included renault, nissan and mitsubishi, a man who once rubbed shoulders with presidents. but he was arrested injapan in 2018 and charged with serious financial crimes. a year later, he fled the country before his trial, hidden in this musical equipment box, and travelled to lebanon. i did not escapejustice. i fled injustice. mr ghosn has always claimed he was the victim of an elaborate japanese conspiracy designed to derail a merger he was planning between nissan and its french partner, renault. but now it's officials in france who want him in custody. they've been investigating claims company money was misused to fund lavish personal spending. he protested his innocence once again. well, first, they're wrong. there was not one euro from nissan that ended up benefitting me, directly or indirectly — not one euro from renault, not one euro from nissan. but the chances of mr ghosn standing trial in france seem remote. at the moment, he's banned from leaving lebanon because of an interpol red notice issued byjapan. he says he would welcome the chance to fight the allegations against him. you've made it clear that you believe you're innocent of all the charges and claims that have been made against you. how confident are you that you could prove your innocence in a court of law? look, i'm totally confident about that. i am ready because it took me a couple of years to start to get all the documents that are necessary to my defence. now i have them, i have testimonies, we have people who are crucial witnesses who are free to talk. people are starting to talk. some documents are coming to me. i'm ready for it, yes, without any doubt. mr ghosn says any trial should take place in lebanon. he's confident he can prove his innocence if he ever appears in court, but the actions of the french a case for him to answer. theo leggett, bbc news. it is the oldest and most prestigious exhibition in the western art world — the venice art biennale opens tomorrow. this year, it's happening against the backdrop of the war in ukraine, of course. our culture editor, katie razzall, met ukrainian and russian artists in venice. serene venice has been shaken by world events. first, its international art show was delayed a year by covid. now, that biennale is taking place in the shadow of war. all of which means, unusually, the art world is focused on ukraine. there is a new damien hirst for a show, defending freedom. and works by maria prymachenko, who is a symbol of the country's national identity. it's about showcasing ukrainian culture. one artist depicts her husband and others who havejoined the army, painted as reports of war crimes against civilians in the kyiv suburb bucha were revealed. and i was even crying because of bucha, and this canvas was laying on the floor and i thought, ok, ironically, connect, you know, because of the... ..wetness of the painting is connected to my tears. russia's pavilion is shut. the artists and curator behind this year's show pulled out when the invasion happened. the only thing to see was an anti—war protest by a russian artist. applause he was surrounded by supporters, and then swiftly by police. he's a sole voice of protest but he does speak for many russian artists, and this russian pavilion is closed — and, in a sense, those closed doors symbolise quite how isolated russia is. but some russian art is being shown at the bienniale, including tapestries by zhenya machneva. it's screaming, it's crying. all my feelings is here. zhenya opposes the war. we should stop it. and every day i want that it stops, but it's hard to face, that each day it's getting worse. the ukrainian pavilion is now centre stage in venice. the artist behind this work, called the fountain of exhaustion, says it is important that his country is represented here, because the russians are attacking notjust ukraine but its culture. they want to level and demolish totally ukrainian culture because it doesn't exist because it's part of russia, you know, they are saying that openly, that the war is a punishment for them, and those who doesn't want to go and to understand that this is only part of russia, they have to be physically eliminated. so whether it is photographs of mothers who have lost sons in the conflict, or a 17th—century icon, these works on show here now reflect a country, a culture, that is fighting for its very survival. katie razzall, bbc news, venice. people all around the world have been marking earth day. it's intended to be a moment to demonstrate support for environmental protection. a number of co—ordinated events have been taking place — as the bbc�*s tim allman explains. in this part of thailand, earth day can look, well, not of this earth. it seemed like a giant flying saucer had landed at this buddhist temple. it was in fact 300,000 led lanterns, laid out to form shape of the continents. translation: the great thing about this is the led lanterns i won't cause pollution and affect the environment. we are all here to try to save and protect the earth. it's biodegradable. made out of chalk. on the other side of the world in the us state of massachusetts, they were painting the trees blue, an all natural non—toxic paint that is supposed to raise awareness of deforestation. an issue of concern for president biden. he signed a measure protecting older forests on federal lands. and with this executive order on earth day we are also showing this moment of maximum threat and urgency can also be a moment of enormous hope and enormous opportunity. in the colombian capital bogota students planting new trees. when it comes to tackling climate change, every little helps. "i think it is good because we are doing our part," said this student. "even the smallest change helps the environment, and since this is a global problem, we are helping by doing our share." and in the florida keys to mark earth day they released a recently recovered sea turtle into the wild. one of the oldest animals known to man, back where it belongs. tim allman, bbc news. photos of prince louis have been released to mark his fourth birthday on saturday. taken by the duchess of cambridge, the photographs show the prince playing earlier this month on a beach in norfolk, in east england. his mother catherine's photos have regularly been used to mark her children's birthdays. prince louis is fifth in line to the throne. you can keep up too late to make to date —— you can keep up—to—date with ukraine and more online. you can get in touch with me on twitter. i am @chrisrogers. goodbye for now. hello there. at this time of year, wind direction can have quite a significant impact on the weather story. west has been best for the last couple of days. in fact, there was nearly 14 hours of sunshine in argyll and bute, an absolutely glorious story here. just down the road in north wales, well, that was the highest temperature recorded in flintshire with 19 celsius. that's because we were sheltered from a fresh easterly wind coming in off a cool north sea. it dragged in a lot of cloud with it. most of the weather action over the last few days has certainly been across europe where we've seen some hideous weather, wet and windy at times across northern spain and portugal, and that's going to continue for the weekend. for us, though, there will be a lot of cloud, and it's been pushing in off the north sea, and the cloud thick enough for some coastal fog which will linger across the far north—east of scotland. but once again, western areas in scotland, northern ireland, north—west england seeing the best of any sunshine. the cloud will break up across england and wales, but we could see a rash of showers into south wales and south—west england as we go through the afternoon. yes, it's going to be another breezy day, so on exposed north sea coasts, it will be noticeably cooler. we're likely to see those temperatures perhaps peaking at around 12 or 13 degrees. but in western areas and maybe into the south—east, where we see that cloud break up and more sunshine coming through, 18 degrees, once again, is quite possible. so, there's that low pressure bringing yet more wet weather and significant snow across the alps in europe. at the same time, we're under this influence of high pressure, but there'll be plenty of isobars squeezed together, so a significant breeze yet again on sunday. that may well help to break up the cloud a little further on sunday, but it will continue to drag in a lot of low cloud and sea fog across the northern isles and far north—east of scotland. 9—11 degrees here, but with more sunshine and fewer showers, 18, once again, not out of the question. then, as we head into next week, the isobars will open up a little, but we can track that wind direction to more of a north—easterly, a cooler source if anything. so, yes, potentially lighter winds, but that's going to drag in a little more in the way of cool air in comparison to of late. so, we keep the theme dry to close out the month of april, but noticeably cooler than we've seen over the last couple of days. take care. this is bbc news. the latest headlines now: the united nations has described the war in ukraine as a "horror story of violations against civilians" and says there's growing evidence war crimes may have been committed. it comes as us satellite images allegedly show a mass burial site near the besieged southern port city of mariupol. the un secretary—general is to travel to moscow for talks with president putin before then moving on to meet with president zelensky in kyiv. a ukrainian deputy prime minister has told the bbc only the un can save the lives of tens of thousands of people stuck in mariupol.