In the deadliest attack, a suicide bomber detonated an explosives-rigged vehicle at a checkpoint south of Samarra, killing five people, among them three police, and wounding seven others, including four police.
And a roadside bomb killed three federal police and wounded two more west of Samarra, a sensitive city home to a revered Shiite shrine that was bombed in 2006, sparking a Sunni-Shiite sectarian conflict that killed tens of thousands of people.
Militants, led by jihadists from the Islamic State group, launched a major offensive on June 9 that has overrun large areas of five Iraqi provinces.
While government forces have since performed better, they have yet to make major gains in offensive operations.
Violence in Iraq has killed at least 5,200 people so far this year, according to AFP figures based on security and medical sources.