The deadly showdown between U.S. troops and Iraqi militants in Najaf dominated Iraq's national conference Monday, with tribal and religious leaders deciding to send 60 delegates to the holy city to persuade a radical Shiite cleric to call off his fighters.

Aides to Muqtada al-Sadr said the cleric, whose loyalists have been battling the Americans from Najaf's vast cemetery and revered Imam Ali Shrine since Aug. 5, awaited the delegates' arrival Tuesday. Al-Sadr's supporters said they welcomed the move. "We are ready to accept any mediation for a peaceful solution," Ahmed al-Shaibany said in Najaf (search).

U.N. Secretary-General Kofi Annan (search) has offered to play "a facilitating role" to help end the violence if all sides agree, U.N. Spokesman Fred Eckhard said Monday.

He said the decision came after Annan spoke to Secretary of State Colin Powell (search), Iran's Foreign Minister Kamal Kharrazi, and his new Iraq envoy Ashraf Jehangir Qazi.

The three-day National Conference in Baghdad was supposed to be a revolutionary moment in Iraq's democratic transformation post-Saddam Hussein, an unprecedented gathering of 1,300 Iraqis from all ethnic and religious groups for vigorous debate over their country's course.

It also was intended to increase the legitimacy of interim Prime Minister Ayad Allawi's (search) government, which is deeply dependent on American troops and money even after the official U.S. occupation ended.

But the violence in Najaf, which resumed Sunday after cease-fire talks broke down, has diverted the gathering. U.S. tanks rolled into the Old City of Najaf to within 500 yards of Iraq's holiest Shiite shrine Monday, witnesses said. Explosions also rocked the cemetery.

Najaf's police chief, Maj. Gen. Ghalib al-Jazaari, said members of al-Sadr's Mahdi Army militia broke into his family's house in Basra, beat up his sisters and kidnapped his handicapped, 80-year-old father.

At the conference in Baghdad, some delegates threatened to walk out in protest of the government's effort to crack down on the militants, while others called for al-Sadr to abandon his uprising. Still others said the crisis only made the conference more relevant.

Late Monday, Iraqis at the conference agreed to send a delegation to meet with al-Sadr, who has vowed to fight "until the last drop of my blood has been spilled."

"I think it would be very risky for Muqtada al-Sadr to stand in its way," said delegate Haider al-Ebadi of the Shiite Dawa party. "The previous negotiations failed because of mistrust. I think they have a chance here."

The delegation will travel in a convoy to Najaf, 100 miles south of Baghdad, early Tuesday. U.N. envoy Ashraf Jehangir Qazi said he would join the mission if invited, spokesman Nejib Friji said.

If al-Sadr agrees to stand down, the conference will have succeeded in turning a crisis that threatened to torpedo the gathering into a startling, symbolic victory showing the potential power of communal solutions in post-Saddam Hussein Iraq.

If he refuses, the conflict will have done little more than distract attention from other pressing issues and damage conference organizers' efforts to project an optimistic image of national unity.

"We hope he will accept it. This country has seen so much violence and so much bitterness, it's time that we seek a way out," said Barham Saleh, deputy prime minister for national security.

U.S. troops have taken the lead in the Najaf fighting, while Iraqi security forces have played a minor role, mainly manning checkpoints. U.S. troops are training Iraqi national guard units for any possible raid on the shrine compound.

Violence persisted throughout Iraq on Monday.

In Baqouba, two civilians were killed and four others were wounded when a mortar hit their house, said Ali Hussein, a medic at the city's main hospital.

Attackers ambushed a U.S. tank and set it on fire in Sadr City, a Baghdad slum and al-Sadr stronghold, the army said. The crew escaped with minor injuries.

"Security is the No. 1 concern of all Iraqis," said conference delegate Radha Taki of the Supreme Council for the Islamic Revolution in Iraq. "And the main security problem these days is the escalation in Najaf."

The Najaf violence halted temporarily Friday as the government tried to negotiate a truce with al-Sadr's fighters. However, in a potentially devastating fluke of timing, talks broke down and fighting resumed as the conference began Sunday.

The conference's main task was to help form a 100-member national council that will serve as a watchdog over the interim government before elections expected in January. The conference also was meant to discuss reconstruction efforts, a persistent Sunni uprising and other key issues while reassuring the public that all groups will have a voice in the new Iraq.

The conference will not decide on a national council until the delegation returns later Tuesday.

Some delegates saw the Najaf crisis as fortuitous and hoped to use the peace mission to show the Iraqi people that the gathering was not only legitimate but relevant.

"It is a normal thing that this issue of al-Sadr draws great attention because there is a fire in all of Iraq. The abnormal thing is to neglect this fire," said Jawad al-Maliky of the Dawa Party.

As the conference started, some delegates threatened to walk out over Najaf as others angrily condemned the government's actions there.

Frantic organizers set up a last-minute working committee to find a peaceful solution. On Sunday, three committee members discussed the plan with Allawi.

Leading the call for peace was the cleric's distant relative, Hussein al-Sadr. His peace proposal listed three conditions: the cleric's militia leave the shrine, disband without fear of prosecution and become a political movement.

"This is not right. We demand Muqtada al-Sadr withdraw from the holy shrine because it's not the specific property of one person. It belongs to everybody," Hussein al-Sadr said.

One delegate said meeting with al-Sadr was more important than the conference.

"He (al-Sadr) is waiting for us," Fawzi Hamza told reporters.

The conference already has had some successes.

Some of al-Sadr's followers, who said they were boycotting, attended for the first time Monday, said Hamid al-Khafaie, a spokesman for the former Governing Council.

"We are happy that al-Sadr's movement is represented here, because we really want to hear their views," he said. "They are an important component of the Iraqi civil structure, and the political process will not be complete without having their views."

Iraq is scheduled to hold January elections to choose a transitional government. That government will convene a national convention to draft a constitution for consideration by voters in October 2005. A vote for a constitutionally based government will follow two months later.