In the Iraqi city of Tikrit, three Iraqis were killed after their boat came under fire from a US helicopter patrolling the Tigris River north of the city.
In al-Saydiya district, south of Baghdad, armed fighters assassinated an Iraqi police officer.
In al-Ghazaliya district, west of Baghdad, a US military vehicle was destroyed in a rocket-propelled grenade attack that was carried out by armed fighters.
In the northern Iraqi city of Kirkuk, an Iraqi was killed and three were wounded when an improvised explosive device, targeting an Iraqi army patrol, exploded.
Also in Kirkuk, a bomb near a Sunni mosque killed one civilian heading to Friday prayers, police official Sarhad Qadir said. Three others were also injured.
US post attacked
In the Iraqi city of Ramadi, a bomber exploded a booby-trapped truck targeting a building used as a military post by US snipers.
US forces immediately closed entrances and bridges leading to the city.
In the eastern city of Balad Ruz, armed fighters killed police chief Colonel Hatim Rashid and another officer at a police station, police Colonel Mudhafar al-Jiburi said. A third officer was injured in the attack, 50km northeast of Baghdad.