The U.S. civilian administrator in Iraq has declared a unilateral cease-fire in the Iraqi city of Fallujah, where U.S. Marines are in their fifth day of battling insurgents.

Paul Bremer said the temporary halt of offensive operations is meant to allow talks between members of the U.S.-appointed Iraqi Governing Council and insurgent leaders. It was not clear yet whether a meeting had taken place.

Mr. Bremer said the cease-fire is also intended to allow the delivery of humanitarian supplies to the besieged town and to allow residents to tend to the dead and wounded. Some 300 Iraqis are believed to have been killed in fighting there this week, as well as several Marines.

But U.S. forces have retained the right of self-defense, and reports from Fallujah say there has been sporadic gunfire since the cease-fire went into effect at noon, local time.

In Baghdad, which one year ago Friday, fell to coalition forces, the atmosphere was relatively calm, until a large explosion rocked an area near the Ishtar Sheraton hotel, that houses foreign journalists and civilian contractors. Initial reports said the blast appeared to be that of a mortar shell. No casualties were reported.

Earlier in the day, U.S. soldiers tore down portraits of radical Shi'ite cleric Moqtada al-Sadr hanging on a column in the same square where a year ago U.S. forces toppled a statue of Saddam Hussein.

Meanwhile, in other parts of central and southern Iraq, U.S. and coalition forces continue efforts to crush a rebellion by Moqtada al-Sadr's al-Mahdi militia.

U.S. General Mark Kimmitt said Friday, the main hot spots are areas in the holy cities of Najaf and Karbala, where the Shi'ite militia has partial control. He said the coalition is taking a passive role in dealing with the militia until Arbaeen observances are over.

More than one million Shi'ite pilgrims are expected in the holy cities for the religious observance, and the coalition has warned them to exercise caution.

General Kimmitt also said he expects U.S. forces to be in complete control of the town of Kut by Saturday morning. The al-Mahdi militia seized Kut Wednesday from Ukrainian troops.

And in Baquba, northeast of Baghdad, clashes erupted after Friday prayers between insurgents and U.S. troops.