The White House has denounced one of the worst bombings ever in Iraq as “barbaric”. At least 175 people have been killed in the town of Kahtaniya, in the north of the country, by four suicide bombers driving fuel tankers. 200 more people have been wounded. US military helicopters have been ferrying the injured to hospitals which are making frantic appeals for blood donors. It’s thought the attacks were aimed at a Kurdish minority religious sect .