At least 40 people were killed in bombings in Iraq on Thursday. It was the worst violence since US Combat troops withdrew from urban areas at the end of last month.

The day's worst carnage hit the northern city of Tal Afar. A suicide bomber wearing a police uniform and carrying a radio and a pistol knocked on the door of an investigator in the anti-terrorism police force.

When the officer opened the door, the bomber detonated his explosive belt, killing the man, his wife and son.

As people gathered in the aftermath, another suicide bomber detonated his explosives belt. The coordinated attack killed a total of 34 people and injured 70.