Iraq's radical Shi'ite cleric Moqtada al-Sadr has ordered his militia to maintain a cease-fire after U.S. and Iraqi forces raided the group's stronghold in Baghdad.

Al-Sadr's office in the city of Najaf issued a statement Thursday saying that any militiamen who engage in violence during the truce will no longer be part of the Mahdi Army.

Earlier in the day, Iraqi and U.S.-led forces raided several homes in Baghdad's Sadr City district, a Shi'ite slum that serves as a Mahdi Army base.

The U.S. military says the troops killed one insurgent in a gun battle and detained 15 others. Several civilians also were wounded.

The military says the operation targeted criminals responsible for attacks on U.S. and Iraqi forces and for kidnapping and murdering Iraqis. U.S. commanders have said they will continue to target rogue Mahdi Army units that refuse to follow al-Sadr's truce.

A unilateral six-month cease-fire called by Moqtada al-Sadr last August is due to expire at the end of this month. It is not clear whether it will be renewed. U.S. commanders credit the truce as a major factor behind a 60 percent drop in violent attacks in Iraq since June.

Some members of al-Sadr's parliamentary bloc have urged the cleric not to extend the cease-fire because security forces, they say, are persecuting militia members.

Also today, Iraqi police say gunmen stormed a house near the town of Baquba, ordered the women and children out, and killed three brothers - all members of a U.S.-backed neighborhood patrol. The gunmen then blew up the building with explosives.

In other fighting, the U.S. military says U.S. forces killed five al-Qaida militants in operations Wednesday near the town of Khalis.

And the U.S. military said today that an American soldier was killed Wednesday when his vehicle was hit by a roadside bomb in western Baghdad.

Some information for this report was provided by AFP, AP and Reuters.