Gunmen ambushed a car carrying American civilians on a road south of Baghdad (search), killing one and wounding three others, the U.S. military said.
The attackers, driving a white sedan, opened fire on the taxi that the Americans were taking to Baghdad from the site of the ancient city of Babylon (search), the survivors told U.S. troops, a statement from the military said Sunday.
U.S. paratroopers learned of Saturday's attack while conducting a patrol in the town of Mahmudiyah, about 15 miles south of Baghdad, and were told the Americans were being treated at hospital there.
The statement said the Americans were part of a "religious group" but did not identify it. There are a number of Christian humanitarian groups working in Iraq.
Insurgents have been waging a campaign of attacks on U.S. troops and their Iraqi allies and have occasionally targeted aid workers. Robbers also prowl highways outside the capital.
A convoy carrying CNN employees was attacked near Mahmudiyah on Jan. 27. Gunmen opened fire on the vehicles, killing two Iraqis working for the network and wounding a cameraman.
Also Saturday, U.S. troops raided a suspected cell of the militant group Ansar al-Islam (search) in the city of Baqouba, 45 miles northeast of Baghdad. Seven suspects were arrested, including four the military had specifically sought, the U.S. command said.
Ansar al-Islam is a radical Muslim group based in Iraq's Kurdish region that is affiliated with Usama bin Laden's network.