Rival Shi'ite factions clash in Baghdad: police

BAGHDAD (Reuters) - Fighting erupted between followers of Shi'ite cleric Moqtada al-Sadr and supporters of a rival Shi'ite faction in several Baghdad neighborhoods on Tuesday, police said.

The fighting was taking place in several neighborhoods of Sadr City, the sprawling slum of about two million people that is Sadr's main stronghold, they said.

Police said Mehdi Army fighters loyal to Sadr were battling gunmen from the Badr Organization, the armed wing of the Supreme Islamic Iraqi Council (SIIC). The Sadrists and SIIC represent the two biggest Shi'ite political blocs in parliament.

Police said the fighting had forced them to leave the Habibiya and Orfaly neighborhoods of Sadr City, along with a third neighborhood close to the slum, al-Maamel.

A Reuters witness in Sadr City reported seeing a long column of U.S. Stryker armored vehicles entering the area.

A spokesman for U.S. forces in Baghdad, Lieutenant-Colonel Steven Stover, said he was aware of clashes between gunmen and police in Sadr City. He had no reports of any casualties.

Stover also said rockets fired at the Green Zone, the diplomatic and government compound in central Baghdad, had come from Sadr City.

The Mehdi Army is meant to be observing a ceasefire imposed by Sadr, but in recent days there has been an upsurge in violence involving the militia.

Militia fighters have complained that U.S. and Iraqi forces are exploiting the truce to carry out indiscriminate arrests. The U.S. military says it only targets rogue Mehdi Army units that have ignored Sadr's ceasefire order.

(Writing by Ross Colvin)