By JIM KRANE, AP

BAGHDAD, Iraq (Sept. 6) - A massive car bomb exploded on the outskirts of Fallujah on Monday, killing seven U.S. Marines and wounding several others, a U.S. military official said.

The strength of the blast sent the engine from the vehicle used in the bombing flying "a good distance" from the site, a military official said on condition of anonymity.

Wounded troops were being treated Monday afternoon, the official said.

U.S. forces have not patrolled inside Fallujah since April, when U.S. Marines ended a three-week siege. The city has since fallen into the hands of insurgents who have used it as a base to manufacture car bombs and launch attacks on U.S. and Iraqi government forces.

The U.S. military has retaliated by launching several airstrikes on insurgent safe houses in the city.

Witnesses said the attack took place nine miles north of Fallujah and destroyed two Humvees.

Medical teams in helicopters swept into the dusty barren site to ferry away the injured. Troops sealed off the area surrounding the wreckage.

With Monday's deaths and those of two U.S. soldiers in a mortar barrage outside Baghdad a day earlier, 985 U.S. service members have died since the beginning of military operations in Iraq in March 2003, according to the Defense Department.