A shaky ceasefire appears to be taking hold in Baghdad's Sadr City after a Shiite leader said allied forces would respect the deal even after clashes left at least 11 men dead and 19 wounded.

The pact was intended to stop seven weeks of fighting between US-supported Iraqi troops and Shiite extremists who fired more than 1,000 mortars and rockets into the Green Zone, home to the government and Western embassies.

But the ceasefire did not start well, with clashes late on Monday and Tuesday morning. Iraqi medics reported 11 killed and 19 wounded. There were women and children among the wounded, said hospital officials.

The Sadr City fighting and ceasefire in Baghdad have brought into question the authority of anti-American cleric Muqtada al-Sadr.

Sadr, who currently lives in Iran, signed a ceasefire agreement in August, but Shiite militiamen have recently ignored those orders.

Lt Col Steve Stover, a military spokesman for US troops in Baghdad, said that the fighting was caused by Shiite factions that have broken with Sadr. Many are thought to be trained and armed by Iranian forces. Iran denies the allegations.

Nevertheless, pro-Sadr clerics negotiated the new ceasefire and one said it was taking hold and would be enforced.

"We signed an agreement and we are loyal to the agreement we reached," said Sheik Salah al-Obeidi, an aide to al-Sadr. "There might be some violations from both sides and we have to try to prevent them."

The deal allows Iraqi forces to take over security in the militia stronghold of Sadr City. Under the compromise, Iraqi forces will try to refrain from seeking American help to restore order.