BAGHDAD, Iraq, Feb. 26 — Leaders of the main Sunni Arab political bloc have decided to return to suspended talks over the formation of a new government, the top Sunni negotiator said Sunday. The step could help defuse the sectarian tensions that threatened to spiral into open civil war last week after the bombing of a Shiite shrine and the killings of Sunnis in reprisal.

That bloodletting has amounted to the worst sectarian violence since the American invasion nearly three years ago, and the possibility of Iraqis killing one another on an even greater scale appears to have helped drive Sunni Arab politicians back to moderation, after they angrily withdrew from negotiations last Thursday.

The Bush administration has pegged its hopes for dampening the Sunni-led insurgency, and withdrawing some of the 130,000 American troops here, to Sunni Arab participation in the political process.

While the Sunni bloc, the Iraqi Consensus Front, has not publicly announced its decision and could still reverse course, Iraqi officials say the talks may resume as early as this week, depending on the level of tension in the streets.

Sectarian violence appeared to be ebbing across Iraq on Sunday, with more people venturing outside for the first time in days. Nonetheless, Shiite militiamen retained control of some Sunni mosques they had raided, and scattered mayhem left at least 14 people dead, including three American soldiers. At least 227 people have been killed since the shrine bombing.

The young spiritual leader of the Shiite militiamen, Moktada al-Sadr, made his first appearance in Iraq since the paroxysm of violence. He arrived in the southern port city of Basra from a trip to Iran, and, in a rare public speech, called for unity between Shiites and Sunnis while demanding a timetable for the withdrawal of American forces.

Blaming the American military for the recent violence, he told Iraqis to "cut off the head of the snake." Thousands of followers, some waving Kalashnikov rifles, cheered in the streets.

The return to talks of the Sunni Arab bloc would be a crucial step in keeping on track the formation of a permanent government, which was mired in troubled negotiations even before the attack last Wednesday. The Sunni negotiator, Mahmoud al-Mashhadany, said Sunni politicians now recognize the need to form a widely inclusive government as quickly as possible to succeed the current interim government, dominated by religious Shiites and Kurds.

"We've canceled our withdrawal from the talks," Mr. Mashhadany said in a telephone interview. "We should hurry up and form a national unity government, to change this hopeless government. In the new government, everyone will handle responsibility."

The Bush administration has been pressuring the majority Shiites and the Kurds to allow significant Sunni Arab representation in the coming four-year government, in hopes of politically engaging the Sunni-led insurgency. The Sunni Arabs are severely underrepresented in the current government because they boycotted elections in January 2005.

The mediation efforts of the American ambassador here, Zalmay Khalilzad, were dealt a serious blow last Thursday, when the leaders of the Iraqi Consensus Front, which is religiously conservative, said they were boycotting talks on forming a government out of anger at the sectarian violence, organized mostly by Mr. Sadr's militiamen after the bombing of the golden-domed Askariya Shrine in Samarra.

The Sunni Arabs presented a list of demands to the Shiite-dominated government, including repairing the damaged mosques and honoring the memory of Sunnis who were killed. On Saturday night, at an emergency meeting of political leaders, the Iraqi prime minister, Ibrahim al-Jaafari, said the demands were valid.

Mr. Mashhadany said Sunday that the Sunni Arabs would remain vigilant for any broken promises from the Shiites. "We don't need words on paper," he said. "We need them to implement these changes."

But he generally struck a conciliatory tone, saying "there's a desire to accelerate the formation of the cabinet" and adding, "This is from the leadership of all the groups — the Sunnis, the Shia and the Kurds."

In the past several days, Iraqi officials have put aside the negotiations to deal immediately with the sectarian violence. If the streets remain calm on Monday, they say, that could prompt leaders to restart the talks.

The Iraqi government announced that on Monday it would lift an extraordinary day curfew it had imposed on Baghdad since Friday.

"We're not yet talking about forming the government," said Sheik Jalaladeen al-Sagheir, a senior Shiite politician. "We want to make sure the air is clear first."

In the past several days, American diplomats have conferred with Iraqi leaders to try to bring all the parties together. The Americans approached several Iraqi officials, particularly Sunni Arabs, requesting their presence at the emergency meeting called by Mr. Jaafari on Saturday night.

"We strongly felt Sunni Arabs had to be there and accept the invitation," one diplomat said.

At the meeting, dozens of politicians formed an advisory council to look into reducing the sectarian tensions. All sides still have major concerns: Some Sunni Arab leaders, for instance, are demanding that the Shiite-dominated police, accused of running death squads and torture chambers, release Sunnis who were arrested during the wave of violence.

Attacks that took place Sunday were, for the most part, less intense than the recent violence. Eight mortar rounds landed near two Shiite mosques in the troubled Baghdad neighborhood of Dora, killing at least 8 and wounding at least 32.

In Baquba, 30 miles northeast of Baghdad, gunmen fired on boys playing soccer, killing two and wounding at least five. A roadside bomb around Baghdad killed at least one Iraqi commando officer in a convoy. A bomb exploded in a Shiite mosque in Basra, causing minor injuries.

The American military said two soldiers had been killed early Sunday in Baghdad by a roadside bomb. Another soldier died from small-arms fire in the evening.

No word emerged on Sunday of the fate of Jill Carroll, the 28-year-old American journalist abducted in early January. Her captors issued a statement through a Kuwaiti television station this month demanding that the Americans and Iraqis release all imprisoned women by Sunday, or Ms. Carroll would be killed. The Americans have said they do not negotiate with militants.

Though the streets of Iraq remained mostly quiet throughout the day, a general atmosphere of anxiety still blanketed the country. The police intensified patrols and checkpoints on the outskirts of Najaf, the southern city that is home to Shiite Islam's holiest shrine and its most revered cleric, Grand Ayatollah Ali al-Sistani. In the Baghdad neighborhood of Zaiyuna, militants who had engaged in firefights by a Sunni mosque in the past two days seemed to have disappeared.

"Today, it's tense but quiet," said Ansam al-Abaiyachi, a women's rights advocate.

Members of the Mahdi Army, Mr. Sadr's militia, still kept control of some Sunni mosques they had stormed last week. They stood guard around the buildings with Kalashnikovs, but many had doffed their black uniforms, on orders from senior Sadr officials. In some instances, they tried to persuade Sunni worshipers that the Shiites had a right to keep the mosque.

That was the case at one mosque on Palestine Street in Baghdad, near Sadr City, the militia's enclave. The Sadr followers occupying it told neighborhood Sunnis that it had been a Shiite mosque before Saddam Hussein's government converted it into a Sunni house of worship. Last week, the militiamen expelled the imam and renamed the building the Ali Mosque, after the martyred son-in-law of the Prophet Muhammad, revered by Shiites.

The militiamen had also set up a checkpoint near the mosque. Policemen tried futilely to persuade them to take it down.

"They're like the Baathists from before," one police officer said, making the comparison with members of Saddam Hussein's Baath Party. "You can't talk to them. You can't say anything to them."

The leader of the Mahdi Army, Mr. Sadr, preached calm in his speech in Basra. He was visiting leaders throughout the Middle East when the violence erupted last week.

His last stop was Tehran, Iran. The Shiites and Sunnis, he said, must "be brothers, and love each other, so that our Iraq can be safe, stable, independent, and free of the occupation."

As the crowd of thousands roared, Mr. Sadr called for a peaceful demonstration to be held against the American-led forces. "We got rid of the accursed Saddam only to be replaced by another dictatorship, the dictatorship of Britain, America and Israel," he said.

In northern Baghdad, in the Sunni stronghold of Adhamiya, young men with Kalashnikovs guarded mosques, still fearful of Shiite assaults. Police officers, generally distrusted by Sunni Arabs, remained at checkpoints on the outskirts of the neighborhood. Makeshift barricades of bricks and stones blocked some roads.

There were signs, though, of normal life seeping back in. Children frolicked in the blazing sun. People wandered around with buckets of fuel or kerosene, carting them home after days spent hunkered down indoors.

The main mosque in Adhamiya, Abu Hanifa, was the scene of a televised joint prayer service on Saturday between Sadr clerics and conservative Sunni imams.

"I think the meetings between Shia and Sunni clerics have helped defuse the situation," said Salam Suhail, who sells automotive spare parts. "Any sectarian war would be a catastrophe for us. We'd rather have a tsunami than a war between Shia and Sunni."

Annotazioni − Abdul Razzaq al-Saiedi and Ali Adeeb contributed reporting for this article.