Nouri al-Maliki, Iraq’s prime minister has ordered the arrest of an Iraqi army colonel who had been responsible for security in the bomb-hit Sadriya district of Baghdad, where at least 140 people were killed on Wednesday.

Mr Maliki ordered the arrest on Wednesday night after a series of car bomb attacks by presumed Sunni insurgents in Baghdad killed nearly 200 people - the deadliest attack since US and Iraqi forces launched a security operation in February aimed at halting the country’s sectarian conflict.