Iraqi officials say assailants killed four Iraqi police and a government-backed militia fighter Saturday, as violence rises ahead of a U.S. troop withdrawal.
In the first incident, the unknown gunmen shot and killed two policemen in their patrol car at a Baghdad checkpoint, then set the car on fire.
Two other police officers were shot and killed at another checkpoint west of the city.
Northeast of the capital, gunmen attacked a security post guarded by members of a government-backed Sunni militia, killing one.
Security forces have been frequent targets of insurgents in recent months as the United States reduces its troop strength in Iraq.
The White House said earlier this week that the U.S. is on track to end its combat mission in Iraq at the end of the month.
Fifty-thousand U.S. troops will remain in Iraq to serve as a transitional force. U.S. President Barack Obama has set a goal of removing all U.S. troops from Iraq by the end of 2011.
Some information for this report was provided by AP and Reuters.