In pictures: Iraq violence

1 of 7 Insurgents in Iraq are stepping up attacks against security forces in apparent acts of retaliation following a major US security operation.

2 of 7 In Baghdad, a car bomb was detonated near a police station. Rescuers who rushed to the scene were ambushed.

3 of 7 Insurgents reportedly used rocket-propelled grenades during the attack.

4 of 7 Some 18 attackers were killed, while a dozen more are reported to have been captured.

5 of 7 A woman stands by a row of shops that were destroyed in the Baghdad bombing.

6 of 7 In the mainly Kurdish city of Irbil, a suicide bomber drove his car into a football pitch, killing a dozen policemen and injuring 100.

7 of 7 The city had been relatively peaceful in recent weeks