There has been another shooting incident involving American troops in the central Iraqi town of Fallujah. Witnesses say U.S. soldiers killed four civilians, while the U.S. military confirms two civilian deaths.

According to the eyewitnesses, the casualties occurred when U.S. troops opened fire on two vehicles late Friday at a checkpoint in Fallujah, about 50 kilometers west of Baghdad. Besides the deaths, at least four civilians were injured, including a young girl.

A U.S. military spokesman said the troops had shot back in self-defense when gunfire erupted from a van.

This is the latest in a string of violent incidents involving U.S. troops in the Fallujah region, which has been a hotbed of opposition to the U.S.-led occupation of Iraq.

In another incident, coalition officials say unidentified assailants fired at least three projectiles, possibly mortars or rockets, at a hotel housing senior officials of the occupation forces. There were no casualties and only minor damage to the al-Rashid Hotel.