with robert fagg, his opposite number from dover. this is bbc news. our top story: in a rare move, us prosecutors have filed involuntary manslaughter charges against the parents of a teenager accused of shooting dead four students at his school in michigan. talks in vienna aimed at reviving the international nuclear deal with iran have faltered with european diplomats expressing disappointment and concern. they say tehran has backtracked on diplomatic progress made . iran s top negotiator suggests that his counterparts should come up with their own proposals. talks are due to continue next week. the us secretary of state antony blinken says iran has some very important decisions to make in the days ahead. the window is very, very tight because what is not acceptable and what we will not allow