NAJAF, Iraq - Four U.S. Marines assigned to the 1st Marine Expeditionary Force have been killed in separate incidents in Iraq's volatile Anbar province, the military announced Sunday.
U.S. warplanes, meanwhile, bombed Najaf's Old City and troops clashed with Shiite militiamen amid fears a plan to end the standoff could collapse. An Iraqi mediator pleaded for radical cleric Muqtada al-Sadr to pull his fighters from the revered shrine at the center of the crisis.
U.S. forces also appeared to have sealed off the Old City where al-Sadr's Mahdi Army militia is holed up, restoring a cordon that had been loosened in recent days, when peace efforts were making progress.
A car bomb also detonated near a U.S. military convoy outside Mosul, the military said. Two children were injured in the blast.
The bomb exploded as the convoy passed a road west of the city, said Capt. Angela Bowman, a U.S. military spokeswoman.
Early Sunday, U.S. warplanes struck the Old City, scene of much of the fighting, and the sounds of shelling could be heard in the streets, witnesses said. Al-Sadr fighters mortared a police station, and U.S. troops and fighters clashed through the morning.
In the afternoon, militants atacked U.S. forces with mortars, prompting another round of clashes that lasted for around a half hour. At least three people were killed and 18 injured during fighting overnight, said Tawfiq Mohammed of Najaf General Hospital.
U.S. tanks were seen in the streets, though not near the Imam Ali Shrine, the holy site that the Mahdi Army has used as a stronghold and refuge since fighting erupted Aug. 5.
Pitman reports little change in the status of a holy site in the Iraqi city of Najaf, while the violence goes on.
The Iraqi government, which had threatened an imminent raid on the shrine last week, took a more measured stand Sunday, saying it was willing to wait patiently as al-Sadr's aides worked out how to turn over the shrine to Shiite authorities here.
"The government will leave no stone unturned to reach a peaceful settlement," Iraqi National Security adviser Mouaffaq al-Rubaie told The Associated Press. "It has no intention or interest in killing more people or having even the most trivial damage to the shrine. We have a vested interest in a peaceful settlement."
An unofficial mediator and distant relative of the militant leader pleaded with al-Sadr to disarm his militants, pull them out of the shrine and disband his militia immediately.
"We are in a race with time," said Hussein al-Sadr, who earlier in the week presented a peace offer that the firebrand cleric accepted. Since then, however, efforts to end the crisis have begun to unravel as al-Sadr's followers bicker with Shiite religious authorities over how to hand over control of the shrine.
Fighting in the nearby city of Kufa on Saturday killed 40 of the militants, according to a source in the Interior Ministry. However, Mahmoud al-Soudani, head of al-Sadr's office in west Baghdad, called the claim "government propaganda" and said only one militant had died in Kufa Saturday.
In separate violence north of Baghdad on Sunday, a car bomb exploded in the town of Khalis, killing two people and injuring 14 others, including a deputy provincial governor, Bassam al-Khadran, who was lightly wounded, Iraqi officials said.
A suicide bomber detonated the car, laden with explosives, as al-Khadran was traveling to work in a small convoy, said Gen. Waleed al-Azawi, chief of police for Diyala province. Both fatalities and seven of the injured were al-Khadran's bodyguards, he said. One civilian was also wounded.
In Jur al-Nadaf, 12 miles south of Baghdad, attackers sprayed a police vehicle with machine-gun fire, killing two policemen before fleeing, said police Col. Adnan Abdul-Rahman of the Interior Ministry.
In Baghdad, assailants fired two mortar shells into the city center on Sunday, wounding at least one civilian and damaging a shop and several houses, said Abdul-Rahman.
In the southern city of Basra, an Iraqi intelligence officer kidnapped nearly a week ago and threatened with death if U.S. and Iraqi forces did not end the violence in Najaf was found dead, his body riddled with bullets, police said Sunday.
In a video shown Tuesday on the pan-Arab Al-Jazeera television station, a group calling itself the Defense of the Holy Sites Brigades said they had snatched the man.
Abdul Jawad's body was found in a deserted area Saturday, said Basra police commander Brig. Gen. Mohammed Kadhim al-Ali. It wasn't clear if the group was behind Abdul Jawad's slaying.
On Saturday in Najaf, U.S. troops and al-Sadr's fighters fought brief but heavy clashes, punctuated by gunfire and explosions, with one blast hitting the street 50 yards from the Imam Ali Shrine.
Interim Prime Minister Ayad Allawi threatened last week to wrest the shrine from the Mahdi Army by force, an operation that risked risked turning the nation's majority Shiites against the government.
Allawi backed off that threat when the crisis appeared on the verge of resolution Friday. Insurgents removed their weapons from the shrine - though they retained control of it and armed fighters remained around it. Al-Sadr said he was prepared to turn the holy site over to representatives of Iraq's top Shiite cleric, Grand Ayatollah Ali al-Husseini al-Sistani.
But the transfer bogged down Saturday amid arguments over its implementation; al-Sadr aides said they tried to give the shrine's keys to al-Sistani's representatives, who refused to accept them.
In a hastily called news conference in Baghdad on Saturday evening, Hussein al-Sadr, who had headed a peace delegation to Najaf earlier in the week, appealed to the militants to end the standoff "to keep the sanctity of our holy sites, to ease the suffering of Najaf and to quiet the situation."
Muqtada al-Sadr himself has not been seen in days, but al-Soudani said Sunday that the cleric was in good health and remained in Najaf.
The standoff has frustrated many in Najaf, who have suffered cuts in their water and electricity, had their streets rocked by explosions and seen scores of their innocent neighbors killed since the fighting started Aug. 5.
"All parties are stalling," said Saeed Mohammed, 41. "There has been no change, only more shelling and clashes that have hurt the city even more."
Meanwhile, guards at a prison in the southern city of Amarah helped 82 prisoners - all common criminals - escape early Sunday, a prison official said.
Fifty-seven of the escapees were recaptured, and the remainder were being sought, said Lt. Col. Nadhim Zayer Hattab, the director of Amarah's Central Prison.
"There was a deal between some prison guards and prisoners," he said. "There was no attack on the prison."