Fighting has erupted between U.S. forces and insurgents in the central Iraqi city of Ramadi, killing at least six people and wounding at least eight others.

Witnesses say the clashes broke out early Sunday in the eastern and central parts of the city.

Meanwhile, the U.S. military says U.S. warplanes destroyed a mortar bunker in Fallujah Saturday. Military officials say several insurgents were around the bunker at the time of the strike.

U.S. forces have been launching artillery and airstrikes against the insurgent stronghold west of Baghdad ahead of what is expected to be a major assault to drive out insurgents.

Some of this information provided by AP, AFP and Reuters.