U.S. Navy Cmdr. Scott Rye, a military spokesman, said a man who fired on the troops died after he was shot and taken into custody. He said an Iraqi woman also was shot but was treated on the site and released.

Local police said two women and an elderly man also were wounded and taken to the hospital, where one of them died. Rye said the military had no information about those claims.

Sadr City has been the frequent site of U.S. raids over the past several months.

Al-Sadr's office in the Shiite holy city of Najaf released a statement threatening to expel militiamen who break his six-month cease-fire, which expires at the end of this month.

The cease-fire order is credited with helping tamp down violence dramatically in Baghdad, along with the arrival of about 30,000 U.S. reinforcements last summer.

Al-Sadr has threatened not to extend the cease-fire unless the government purges rival Shiite militiamen he alleges have infiltrated the security forces and are targeting his followers.

The military also announced the death of a U.S. soldier killed by a roadside bomb Wednesday in western Baghdad. At least 3,950 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count.

North of Baghdad, the top U.S. military commander in Iraq said he did not want to see the remainder of U.S. forces cut back too quickly after the withdrawal of an extra 30,000 troops by summer.

"Everything beyond that (reduction of the surge force) we would very much want to make conditions-based. And again, that has been the guidance from the president on down," Gen. David Petraeus said at Balad Air Base, 50 miles north of Baghdad, where he opened the first USO facility in Iraq.

On Wednesday, Defense Secretary Robert Gates declined to endorse Petraeus' call for a pause before further troop reductions.

"It's clear that Gen. Petraeus' views will have a very strong impact on this, but I think the president will need to hear other points of view as well," Gates said.