Armed militants have attacked a prison in the Iraqi city of Tikrit, killing at least 12 guards and freeing about 90 inmates, officials have told the BBC. They say a suicide bomber detonated a car bomb at the gates of Tasfirat prison and clashes between militants and security guards followed. Some of the escaped inmates were reportedly al-Qaeda members. The prison was later retaken from the gunmen by security forces, reports say. A curfew is now in place in the area.