there s been heavy bombardment of the territory overnight; the head of the israeli army has called for the military campaign in gaza to be stepped up. israeli tanks are reported to be slowly advancing towards the centre of khan younis and there are reports of house to house fighting in the city. the head of the world health organization has said the war in gaza is having a catastrophic impact on healthcare there. tedros adhanom ghebreyesus warned health workers are having to work in unimaginable conditions in a desperate effort to help civilians. our correspondent hugo bachega has the latest. this is nasser hospital in khan younis, and the aftermath of another night of unrelenting israeli attacks. in the chaos, a father desperately searches for his son. mohamed abu shihab says a sniper opened fire when he was in his house giving water to his two sons. the oldest was wounded. the youngest killed. the sniper killed my son, i want to see my son, he says. this footage from the