At least 69 people, including three US soldiers, were killed when insurgents attacked several targets across Iraq on Thursday, according to reports.
Over 270 people were wounded in the coordinated attacks against police and government buildings, less than a week before the handover of sovereignty.
Police stations in Baqubah, Mosul and Ramadi were the worst hit, CNN quoted coalition officials as saying.
In Baghdad, the Iraqi Health Ministry said 66 people were killed and 268 people wounded in the attacks nationwide.
Its figures did not include American casualties.
Three car bombs hit separate targets in Mosul, killing one US soldier and wounding eight others (three US soldiers and five Iraqi police officers), according to a coalition news release.
Two American soldiers were killed in Baqubah after their patrol was ambushed.
A multiple rocket-propelled grenade attack hit the central police station in Ramadi, killing seven police officers and a member of the Iraqi Civil Defence Corps, Iraq's new army.
Twelve policemen were wounded along with three ICDC members, CNN quoted a local journalist as saying.
There were also reports of violence in Fallujah too.
The attacks came after coalition officials warned of an expected rise in violence in the lead up to the June 30 transfer of power to an interim Iraqi government.