The U.S. military in Iraq says its troops have repelled several attempted ambushes on Sunday, killing 54 Iraqis, wounding 18, and capturing another eight in the town of Samarra, near Tikrit. The number of Iraqis killed by U.S. troops may be the largest since President Bush declared an end to major combat in Iraq on May 1.

A U.S. military spokesman says soldiers with the Army 4th Infantry Division fought off a series of ambush attacks on Sunday in Samarra, north of Baghdad.

Lieutenant Colonel William MacDonald told reporters that U.S. troops, traveling in separate military convoys, were attacked with mortars, grenades and automatic weapons. The troops returned fire, killing dozens of attackers and destroying three buildings the attackers were using to fire on the soldiers.

Lieutenant Colonel MacDonald says many of the attackers wore the uniform of the Fedayeen, a paramilitary force loyal to ousted Iraqi leader Saddam Hussein. He says there is evidence that Fedayeen militiamen may have coordinated the attacks.

It is still unclear whether the Fedayeen was also involved in a series of ambushes on foreign nationals in the Tikrit-Samarra area. Twelve civilian and military personnel from Colombia, Japan, South Korea, and Spain have been killed in separate attacks in the past two days.