The first bombing in Kirkuk was the deadliest of the attacks, killing eight people and wounding another eight, the officials said on Wednesday.

It was followed by a roadside explosion targeting the Kirkuk police chief's convoy and a car bomb that exploded nearby, killing two people and wounding nine between them.

In Tarmiyah, north of Baghdad, a suicide bomber on a motorcycle attacked a police checkpoint, killing one policeman and wounding four people, while a roadside bomb in the northern city of Mosul killed another policeman and wounded two.

Violence in Iraq has fallen from its peak in 2006 and 2007, but attacks remain common, killing more than 200 people in each of the first four months of this year.