Assailants fired rocket-propelled grenades at a checkpoint in Baghdad's southwestern suburbs, killing one U.S. paratrooper and wounding another, a military statement said Wednesday.

It said the soldiers from the 82nd Airborne Division's (search) 2nd Brigade were manning a weapons collection on Tuesday afternoon when a van pulled up about 250 yards from the checkpoint and a number of men exited. They fired two RPG rounds at the squad and then fled down the alleyway, the statement released by the U.S. Central Command said.

One of the grenades fell short but the other exploded killing one of the paratroopers and seriously injuring another. He is listed in critical condition.

Despite the ouster of Saddam Hussein's regime on April 9, U.S. troops have continued to be attacked, mainly in central and western Iraq. Dozens of soldiers and Iraqis have been killed or wounded in daily skirmishes.

Meanwhile, U.S. troops staged a massive crackdown north of Baghdad on suspected Saddam loyalists and Baathist (search) paramilitary groups believed to be behind the spate of attacks, the Central Command said Wednesday.

It said 397 suspects had been arrested so far in a massive sweep near the town of Balad (search), about 40 miles north of the capital. A large quantity or arms and ammunition was seized in the ongoing operation.

On Tuesday, the military said that a total of 205 coalition troops had died since the beginning of the U.S.-led invasion of Iraq.

Of those, 135 were killed in hostile activities and 70 in friendly fire incidents or other accidents. A total of 627 service members were injured since the beginning of Operation Iraqi Freedom on March 20, the military said.