The uk Terror Threat has been increased to critical, the highest level, meaning an attack may be imminent. Its in the wake of a bomb explosion on a rush hour train in london. British police say they are treating the explosion as a terrorist incident. 29 people were injured. So called Islamic State says it carried out the attack. It happened at the height of the morning rush hour as a train pulled into the station at Parsons Green in south west london. The bbc understands that the bomb, described as a homemade device, had been fitted with a timer, but it failed to fully detonate. Whoever planted it is still on the run. The first of our reports is from our special correspondent lucy manning. On the floor of the tube, still in flames, it was supposed to blow up the carriage. That bag is on fire. It caused panic, fear, some injuries, but thankfully it didnt kill. Guys, lets get away and move to the end of the platform. At 8 20am, this train, packed with commuters, had just arrived at Parsons Green. It was loud enough to make me wonder what the bang was, and i looked round and this wall of fire was just coming towards us. I turned left and i saw the fireball surge towards my side. Luke walmsley was in the carriage listening to music. A bang and then a flash to my left. Almost immediately, sort of a surge of people screaming and running towards me. The improvised bomb was in a white bucket, with wires attached, in a lidl freezer bag. Within minutes, armed police, fire crews and ambulances arrived. It was clear there were some injuries. No one allowed through here, yeah . Burns and, from the stampede after, nearly 30 taken to hospital. This womans commute to work ending in a very different way. Relieved to be safe. A large area around Parsons Green tube station has been cordoned off and this afternoon the police announced they were evacuating local residents living closest to it, to allow them to try and make that device left on the train a bit more stable. As so called Islamic State said it carried out this terror attack, the police hunted the would be bomber and the Terror Threat level to the uk was raised. The joint terrorism analysis centre, the independent organisation which is responsible for setting the threat level on the basis of available intelligence, has now decided to raise the National Threat level from severe to critical. This means that their assessment is that a further attack may be imminent. The army will now replace Police Officers at some locations, as hundreds of detectives search for who planted this bomb. This is a very complex investigation which is contining at speed this is a very complex investigation which is continuing at speed with the full weight of the london counterterrorism policing resources assisted by colleagues from around the country and our Intelligence Agency partners, such as mi5. For those who walked out of the tube carriage today, there is, of course, relief. But with a bomber on the run and fears that another attack could be imminent, these are tense times for those whose job it is to catch him. The bomb is being examined by forensic teams and officers are looking through cctv at the station for clues about who planted it. Our security correspondent Gordon Corera reports. The device at the heart of the investigation. The ongoing hunt for the person who planted has now lead to the uks threat level moving up to critical. Its highest level. The makeshift bomb will have yielded some clues in that hunt. Like these wires coming from the bucket, used to try and trigger an explosion. They look similar to these Christmas Tree lights that a birmingham man planned to use in a home made device before he was arrested. Such improvised devices do not always go off properly. That was the case on july 21st, 2005. Experts believe todays bomb also didnt explode as intended. The size of the device that was employed was quite significant. And had that device functioned in its intended and designed mode, wed have seen considerable casualties. Many people injured and probably many people killed. The explosive may have been a compound called tatp. This footage from Brussels Airport and metro shows the devastation when it detonates properly, more than 30 were killed. Its also thought to have been used in the Manchester Arena attack this year. That involved a suicide bomber. But todays attacker wanted to get away and used a timer. That is similar to damon smith, seen here leaving a timed device at North Greenwich a year ago, which was spotted before it went off. Today, hundreds of counterterrorism detectives have been deployed in this investigation. Theyve been forensically analysing this device, looking for fingerprints and dna. Theyve also been scouring cctv images, looking for an individual carrying this bag onto the tube and then getting off without it. That will have been the starting point for their manhunt. Mi5 are helping the investigation. They will want to know if the individual was part of a group or acted alone and, as has often been the case recently, if they were previously known to authorities. Unfortunately it would not be a surprise and this concept of a lone wolf now would more accurately be described as a known wolf. Increasingly attacks, when they happen, have been committed by individuals who were known in some way to either the Counterterrorism Police or mi5 beforehand. 0fficials here have reacted with irritation to this tweet from donald trump theresa may responded that it was never helpful to speculate about an ongoing investigation. For the fifth time this year, the country is dealing with the aftermath of a terrorist attack. And tonight, with no sign yet of an arrest, officials felt they had to raise the threat level amid fears the danger has not yet passed. You can keep up to date with the manhunt in london, following the Parsons Green attack, by going to our website where there is also more eyewitness accounts and analysis. Just click on our website bbc. Com news or download the bbc news app. Lets take a look at some of the other stories making the news. Hundreds of protestors have been blocking streets of the us city of st louis in missouri. They are protesting against the acquittal of former police officerjason stockley who is white from a murder charge following the 2011 shooting of Anthony Lamar smith, who was black. More than 500 protesters marched chanting no justice, no peace, and some held black lives matter signs. The parliament of iraqs autonomous kurdish region has voted to go ahead with a controversial referendum on independence in ten days time. The countrys Central Government in baghdad, which is very much against any move that might lead to the kurdish area breaking away, says the referendum is unconstitutional. The Prime Minister of iceland has called for a snap election after a party quit the Coalition Government over a judicial scandal. Prime minister Bjarni Benediktsson said he preferred the election to be held in november, almost a year after the last snap vote which was triggered by the Panama Papers scandal. The United NationsSecurity Council has again condemned north korea for carrying out what it called a highly provocative missile test on friday. However, there was no mention in the un statement of any further sanctions. The north Korean Leader, kim jong un, has announced that his countrys Nuclear Programmes will continue, despite sanctions, in order to have an equilibrium with the United States. Bill hayton reports. North korea is celebrating, another successful test for its hwasong i2 ballistic my soul, and missile, and kim jong was there to congratulate the scientists. He told them it was his aim to establish a balance of force with the United States, so it cannot threaten his country with military action. But on a visit to an airbase near washington, President Trump said the us would never be intimidated. After seeing your capabilities and commitment here today, i am confident that ever at our options in addressing this threat are both effective and overwhelming. In new york, the un Security Council discussed the situation for the second time this week. This time, there was no new resolution, only a press statement strongly condemning the missile launch, and urging compliance with existing sanctions. And russia says the us has to get serious about talks with north korea. We called on a us partners and others, to implement political and others, to implement political and the traumatic solutions that are provided for the resolution, and without incrementing peace we also will consider it as non compliance with the resolution, not fully in commenting the resolution. But as russia and china urged patients, the us says it is running out of time. It wants an end to north koreas missile and Nuclear Programmes, but with those programmes making rapid progress, the choices facing World Leaders are becoming more difficult. The United States wants china to do even more. But as our china editor Carrie Gracie explains, its difficult for china to pressurise north korea as much as us wants it to. I am in north east china, near the north korean border, as you say, and it is an area where they remember with pride the korean war. Memorials like the one behind me, which they call a war against the United States to assist korea, and that gives you some sense of the difficulties they face, that historical memory, economic reasons, strategic reasons, and reasons of sheer self preservation against a vengeful north korean dictator. All those reasons holding back from abandoning the north korean regime absolutely. So theyve been trying to hold the position, as you see again today, with their defensive response to american pressure, formal acute sanctions against north korea. For more acute sanctions against north korea. They say, we are implementing the existing resolutions to the letter at Enormous Economic cost ourselves. All sides need to ratchet down the tension, according to china. At the end of the day, with every provocative north Korean Missile test, nucleartest, china is coming under increasing pressure. The ground beneath it is shrinking notjust internationally but at home, because the chinese public is increasingly concerned about the nuclear threat, and chinas Foreign Policy experts increasingly say north korea is strategically a liability and not an asset. Stay with us on bbc news, still to come the worlds first Museum Dedicated to street art opens its doors this weekend in berlin. We take a look inside. Freedom itself was attacked this morning, and freedom will be defended. The United States will hunt down and punish those responsible. Bishop tutu now becomes spiritual leader of 100,000 anglicans here of the blacks in soweto township, as well as the whites, in their rich suburbs. We say to you today, in a loud and a clear voice, enough of blood and tears enough translation the difficult decision we reached together was one that required great and exceptional courage. Its an exodus of up to 60,000 people, caused by the uneven pace of political change in eastern europe. Iam free this is bbc news. The latest headlines the Terror Threat level in the uk is raised after an explosion hits a morning rush hour commuter train in london. The north Korean Leader says his country will meet its Nuclear Ambitions after the us strongly condemns the missile test on friday. We will stay with north korea. We will speak to a special adviser with the us state department. She told the us state department. She told the bbc that President Trumps threats of action against north korea is not really a new tactic. Threats of action against north korea is not really a new tacticm is ported to understand military options have always been on the Table Service controversy all this hype about President Trump is now put on the table and its every us president who has had it on the table since president truman. We have to understand that this is a very serious problem and it is a threat but it is a threat to Global Security because north koreas continued flagrant violation of treaties, including the npt, really threatens the global non proliferation regime and this has consequences for every country, including the uk, all the european powers. Certainly the United States but the future of global stability to its far more than just north korea. This is really a test of collective security and the un itself and if the United Nations is unable to take strong action that includes russia and china, really taking serious action instead of just passing resolutions, that i think that also unravels our system today. United nations human rights experts are extremely worried about the arrest of an egyptian lawyer who was detained as he was about to fly to switzerland to meet them. The lawyer, ibrahim metwaly, was due to speak to the Un Working Group on enforced disappearances about cases including that of giulio, the italian doctoral student who was tortured to death in egypt. From cairo, 0rla guerin reports. Lawyer ibrahim metwaly, who dared to fight for egypts disappeared, including his eldest son, amr. Last sunday, at cairo airport, he disappeared himself. He wound up here at the high security tora prison complex, instead of addressing un experts in geneva. Now the lawyer is facing charges of illegally founding an organisation for families of the disappeared. His younger son abdel moneim, also a campaigner, told me he knew the risks, but he wanted to speak for the disappeared, like the murdered Italian Giulio regeni. Translation my father actually expected that he might be stopped at the airport, but he chose not to let fear control him. He took the risk to bring the voice of the victims, to the end, to the entire world. Your brother has disappeared, your father is now behind bars. Are you worried that you could be next . Translation i am living with this fear. It is difficult, but history will remember that i did something. Human Rights Groups say as many as 1,300 people have disappeared off the streets in egypt over the past two years, taken by the military or National Security agencies. They say most reappear weeks or months later, in custody, having been tortured. Last year, the italian researcher giulio regeni was tortured to death after he vanished in cairo. Egyptian authorities denied involvement, but rome recalled its ambassador. Though there has been nojustice for regeni, a new italian ambassador has just arrived here. Human rights campaigners say that sends the wrong message to the egyptian government. It has already changed, just by announcing that the ambassador is coming back to egypt. We had a website blocked, we had members arrested, and the government feels entitled to do whatever it wants. How serious could the consequences be . I think the plan for the government is to silence anybody who speaks out on enforced disappearances. We asked Egypts Interior Ministry for an interview or comment about forced disappearances. It didnt respond. But, in the past, the ministry has said there is no such thing in egypt, not a single case, and any allegations to the contrary are part of a Propaganda Campaign against the government. Now, for 13 years it has been sending home some of the most remarkable images of saturn. But earlier today, cassinis mission came to an end, when the space probe plunged into the planets atmosphere. During its epicjourney, cassini documented extraordinary discoveries and gave us new insight into this mysterious planet. Our science editor David Shukman has more. It has been a journey that sounds like something from science fiction, nasa conjuring up animations of the cassini spacecraft flying around the spectacular rings of saturn. But this really did happen, and these are some of the images the mission actually captured. The planet seen from closer than ever before. The strange detail of its rings. A jetstream in the shape of a hexagon. And an utterly weird collection of moons. But today, the expedition had to come to an end. Im going to call this the end of mission. At mission control, in california, hugs and applause. For many, it has been the work of a lifetime, and no surprise there were very mixed feelings as the final signal reached earth. Well, its been a part of my life for 20 years. Weve spent day in and day out thinking about cassini, planning the observations, focusing on the science. My career has been based on cassini, so its really hard to see that go. Saturn is the most distant world to have been explored for so long. And the cassini spacecraft, which is almost as big as a bus, has achieved something never attempted before. It has given us unprecedented views, and these have led to dozens of discoveries. The mission is described as one of the most remarkable journeys of exploration, while it has been orbiting saturn for a staggering 13 years. Now, it is one of saturns moons, called enceladus, that has produced the most startling revelation. Plumes of vapour were spotted blasting out of it. Now, this turned out to be water. So lets take a closer look inside what we now know, that under a covering of ice, there is an ocean. And scientists have come to an amazing conclusion that in here there is every ingredient needed for life. This opens up a whole new realm of possibilities in the search for life beyond earth. And the discovery of conditions on moons like enceladus is a real breakthrough for scientists like linda spilker, who started her career at nasa three decades ago, when the mission began. We want to know, is there life on enceladuss ocean . Could there be oceans inside of other moons . It will take future missions to go back and answer those questions. The mission captured these images of saturns moon titan, and this is the sound the spacecraft recorded. To make sure cassini didnt contaminate any of the worlds where there may be life, it was sent to its destruction. But it has raised some tantalising new questions. David shukman, bbc news. The new Museum Dedicated to graffiti is opening irving. Opening in berlin. Is this art or a public eyesore . The german capital as famous or notorious, depending on your point of view, or its graffiti. Now a museum has been set up devoted to this unique form of street art. Urban nation will host the works of around 150 international and local artists showcasing their dynamism and the variety. Translation urban contemporary art is the logical next step to follow what is happening on the street. I think this can be an archive aiming to tell a story for the first time from the deep end at the beginning until now, that is what we are trying to show here. Berlin already has a venue for street art, a huge stretch of the wall that divided the city during the cold war. The eastside gallery telling the countrys story and becoming a memorial to peace. Graffiti asked artists hoping that were berlin leads, others will follow. I think its a nice thing that a museum is happening because the artists who have been a part of this scene and movement for a long time are now getting the respect that they deserve and its nice that its looking back through the history and its picking out different areas from it. The first exhibition is called art mile and fittingly enough, it will take place on the streets. To the sad news that cult american actor Harry Dean Stanton has died aged 91. Paris, texax, cool hand luke, alien and godfather ii. He often played loners and offbeat characters. He was also a talented musician, paying guitar and harmonica and singing with a tenor voice. He served in the us navy in the Second World War and fought in the battle of okinawa. He died peacefully at cedars sinai hospital in los angeles. After several days of quite cool, showery weather, only subtle changes taking place this weekend. There will be fewer showers around by the time we get to sunday. Throughout the weekend, occasional sunshine. In it, it feels quite pleasant. In the showers, it feels quite cold. Some quite chilly nights around, as well. Perhaps a touch of frost in a few places. It is chilly because there has been a flow of air from the north. High pressure to the west of us, low pressure to the east. The air coming down from the north of these pressure systems, and its unstable air, bringing showers. A few of the showers for western parts of wales, cornwall, devon, a few near north sea coast zones, into northern scotland, as well. But away from the showery areas, and most of us will be away from the showery areas, were likely to start the day with some pleasant sunshine. Just some areas of cloud and there, but where youve been clear for any period of time overnight, it will be a chilly start. So temperatures are only gradually recovering as we go through the morning. It is still on the breezy side. Youll certainly notice that across northern scotland, and here were getting a fair few showers coming in on that stiff breeze. So on through the day, then, where you start with some sunshine, the cloud is going to build. Therell be the threat of a shower. Where you start cloudy, you may well see the sunshine come they out for a time, but there is still the threat of a shower. And it could be we see a longer spell of rain moving into parts of western scotland and into Northern Ireland. The showers get going elsewhere. There could be some heavy downpours around, especially across some eastern parts of england, that could come with a rumble of thunder. But everywhere at risk of getting at least one shower moving through that may be heavy. Temperatures into the mid teens. Now, as we go on through into the evening, the chance again for another spell of rain, this time affecting parts of wales, south west england. And even overnight, saturday night into sunday, there could be some heavy rain for some into south west england, maybe around lion bay. Heavy showers close to the south coast, whereas many other places will become dry, and it is going to be much cooler in rural spots compared with towns and city centres. For some in scotland, maybe Northern Ireland too, we will get close to freezing, for a touch of frost as sunday begins. Maybe one or two mist and fog patches, because there are lighter winds for part two of the weekend, on sunday. As High Pressure begins to nudge in, and it will give mainly dry weather to scotland, Northern Ireland, variable cloud. Wales and western england will see relatively few showers, but elsewhere across england, a scattering of showers that could be on the heavy side, but by no means everyone will get one. With lighter winds, more seeing some sunshine. It will feel a little bit warmer by the time we get to sunday. But monday and tuesday is looking pretty quiet. This is bbc news the headlines britains Prime Minister has raised the countrys Terror Threat assessment to the highest level following a bomb explosion on a rush hour train in london. Theresa may said security analysts had concluded that a further attack might be imminent, and there would be more armed police on the streets. The United NationsSecurity Council has strongly condemned north korea for carrying out its latest missile test calling it highly provocative. But after an emergency meeting, the un said there would no further sanctions, for now. North korea fired a missile over japan for the second time this month. After twenty years in space, the Cassini Mission to the ringed planet saturn has come to a spectacular end. The probe had run out of fuel and the Us Space Agency nasa had commanded it to destroy itself by plunging into the planets atmosphere. Gavin gray will be here at two oclock