The attack occurred in front of police units standing near the entrance of a local government and court complex. At least 39 people were wounded.

Baquba is the capital of the restive Diyala province - one of the most dangerous parts of Iraq.

The attack comes as figures show violence across Iraq has dropped to a four-year low.

However, correspondents say militants are still capable of launching deadly attacks. On Tuesday, a car bomb explosion at a busy bus stop in northern Baghdad killed 51 people and left another 75 wounded.

It was the deadliest bombing in Iraq's capital for weeks, following a security drive by Iraqi and US forces.

BBC