At least 56 people were wounded in the fighting that began Saturday night and continued into daybreak Sunday, al-Alam reported.

Fighting broke out even though radical Shiite cleric Moqtada Sadr Friday called for an end to fighting between Iraqi security forces and his Mahdi Army forces.

The latest deaths bring to more than 400 the number of people killed in Sadr City since March 25, when Prime Minister Nouri al-Maliki ordered a crackdown on militias.

Speaking on al-Arabiya television Saturday, Maliki set four conditions for ending the military assaults.

"We have four demands, not more, that all those carrying arms -- not just the Mahdi Army -- should adhere to," Maliki said. "Handing in all heavy and medium weapons, and not interfering in the work of government departments.

"Never interfere in the tasks of the police and army, so that police and army would operate everywhere -- in Sadr City, Basra and Mosul -- without any objections," he said.

Coalition forces discovered a cache of explosives Sunday in the Rashid district of Baghdad.

U.S. and Iraqi forces came under hostile fire, U.S. military officials said, killing one suspect during the exchange.