Iraqi officials and hospital sources say a series of bomb blasts have killed at least 12 people and wounded 23 others.
The deadliest of the attacks took place in the northern city of Kirkuk, where two car bombs and a separate roadside blast targeting the city police chief's convoy killed nine people.
In Tarmiyah, 50 kilometers north of Baghdad, a suicide bomber on a motorcycle attacked a police checkpoint, killing two policeman and wounding four people, while a roadside bomb in the northern city of Mosul killed another policeman and wounded two.
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.
Some information for this report was provided by AP, AFP and Reuters.