U.S. forces clashed Monday with gunmen protecting the house of radical Shiite cleric Muqtada al-Sadr (search) in the holy city of Kufa (search). One woman was killed and three people were wounded, a hospital official said.

The U.S. military had no immediate comment.

At least six U.S. military vehicles entered the Zahra area in Kufa near al-Sadr's house, which is protected by his militia, the Mahdi Army, witnesses said.

Heavy gunfire and a mortar barrage set cars on fire before Iraqi police intervened and the U.S. forces withdrew, witnesses said.

"One woman was killed and we have three injured," said Ajwak Kadhim, director at Al-Hakim Hospital in Kufa, 100 miles south of Baghdad.

Al-Sadr, who is wanted by U.S. forces on an Iraqi warrant for the April 2003 murder of a moderate cleric in the nearby city of Najaf (search), was in his house at the time, witnesses said.

The radical cleric, who has grassroots support for his anti-coalition stance, began a two-month rebellion in early April after the U.S.-led occupation authority closed his newspaper and arrested a key aide. A series of truces ended the fighting, and the issue of whether to arrest al-Sadr was dropped without resolution.