A shaky cease-fire appeared to take hold Tuesday 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 U.S.-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 cease-fire did not start well, with clashes late Monday and early Tuesday.

Iraqi medics reported 11 killed and 19 wounded, but the U.S. military said Tuesday they could only confirm the deaths of six militants. The identities of those were not immediately clear. There were women and children among the wounded, said hospital officials, speaking on condition of anonymity because they were not authorized to talk to the media.

In unrelated violence in northern Iraq, a roadside bomb attack killed five Iraqi soldiers Tuesday in Mosul, police said, also speaking on condition of anonymity because they were not authorized to talk to the media. Iraqi troops and U.S. soldiers have launched an operation against Sunni extremists in that northern city.

A U.S. soldier was killed just before dark Tuesday when a roadside bomb exploded next to his vehicle in northwest Baghdad, the military said. The soldier's name and unit were withheld until the family could be notified.

At least 4,077 U.S. military personnel have died in the Iraq war since it began in March 2003, according to an Associated Press count.

The Sadr City fighting and cease-fire in Baghdad have brought into question the authority of anti-American cleric Muqtada al-Sadr. Sadr, who currently lives in Iran, signed a cease-fire agreement in August, but Shiite militiamen have recently ignored those orders.

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

Nevertheless, pro-Sadr clerics negotiated the new cease-fire and one said Tuesday 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 on Wednesday. "Any attack against residential areas, government offices and the Green Zone are prohibited from Sadr City or from another area," the agreement said.

Under the compromise, Iraqi forces will try to refrain from seeking American help to restore order. U.S. military officials on Sunday said they would follow the Iraqis' lead. The Sadrists rejected calls by Prime Minister Nouri al-Maliki to surrender weapons, saying Mahdi fighters have no "medium or heavy weapons."

But Stover blamed the so-called "special groups" for a failed surface-to-air missile attack on a helicopter gunship over Sadr City on Saturday. The missile was fired from an unknown location in eastern Baghdad but missed the target, he said.

The missile harmlessly exploded, and the rocket body landed in Azamiyah neighborhood, where it was recovered by allied Sunni fighters and handed over to the U.S. military. Stover refused to release any details on the missile type.

The missile attack came a day before the four-day cease-fire went into effect Sunday.