Although there have been no claims of responsibility for much of the unrest, which has drawn international condemnation, officials are concerned about a resurgent al Qaeda emboldened by the civil war raging in neighbouring Syria.
Attacks struck across the country, from the northern hub of Mosul to Kut in the south. They cut down civilians as well as security forces in a wide variety of incidents targeting markets, bus stations, a funeral tent and the convoy of a top police official, security and medical sources said.
Babil province, south of Baghdad, suffered the lion's share of the car bombs, as a half-dozen struck provincial capital Hilla and nearby towns, killing six people and leaving dozens more wounded.
Another vehicle rigged with explosives targeting Salaheddin provincial police chief Major General Juma al-Dulaimi killed three civilians and wounded two others.
Dulaimi himself escaped unharmed from the blast in the restive city of Tikrit, which lies north of the capital. A suicide car bombing at a police checkpoint near Samarra, also in Salaheddin, killed three police and wounded three more. Two more car bombs in predominantly-Sunni Salaheddin and two others in Wasit.