More than 550 civilians, including at least 115 children, have been killed in the street fighting and air strikes that have claimed more than 1,000 lives in Yemen since 26 March, according to the UN. The UN children???s agency, Unicef, said at least 64 children had been killed by air strikes, 26 by unexploded ordnance and mines, 19 by gunshots, three by shelling and three by ???unverified causes r