In what appeared to be coordinated strikes, bombers, some driving cars packed with explosives, attacked sites in the town of Rawa, 160 miles northwest of Baghdad. Another bomber hit a busy street in the northern city of Samarra.
No-one claimed responsibility for the blasts, though Sunni Muslim insurgents, including al Qaeda, have regularly targeted security personnel and others working for the Shi'ite-led government.
One attacker drove a car up to a checkpoint on the main road into Rawa and blew himself up.
Another targeted a police station and a third the house of the mayor, seriously wounding him and killing at least three others.
Around 7000 people have been killed in acts of violence in Iraq so far in 2013.