U.S. Marines discovered a car bomb factory Monday in a western Iraqi town near where 20 members of the American unit were killed last week, the U.S. military said.

Six vehicles rigged with explosives were found in the hideout in the northern part of Haqlaniyah, one of a cluster of towns in western Anbar province (search) long believed to be a stronghold of Iraqi insurgents and foreign fighters.

"All of the rigged vehicles were destroyed and secondary explosions were observed by the Marines," a Marine statement said.

U.S. and Iraqi forces also found five roadside bombs Monday on a road in Haqlaniyah, the statement said. All were detonated in place, it said.

Marines (search) have been pressing a sweep of Haqlaniyah and other communities in the area despite the deaths of 20 of their comrades last week. Six members of a Marine sniper team died in a firefight Aug. 1, and 14 Marines and a civilian translator were killed by a huge bomb two days later.

There have been no small-arms attacks on Iraqi soldiers or Marines in the area in the last two days, the U.S. statement said.

On Sunday, U.S. Marines and Iraqi soldiers discovered a bomb in a building in Haqlaniyah (search). Three 155 mm artillery rounds, weighing more than 100 pounds apiece, were wired to a desk inside the building, the U.S. statement said.

Marines destroyed the bomb where it was found after determining it was too dangerous to remove it.