The antigovernment protest on Friday was about the same size as the week before, only more peaceful. Today on the same stretch of street where gunfire broke out a week ago, men sat leisurely playing chess. Another group of men walked by chanting “the people want to prosecute Ali Saleh,” a variation of the popular chant heard recently in many anti-government protests throughout the Arab world, "the people want the regime to fall.”

Photos of some of those who were killed last Friday were hanging on many tents and walls, and also on the main door of the house of the governor of Mahweet, a nearby district, from which a sniper was shooting last Friday.

Most of those in the crowd carried red placards that read “The Friday of Departure,” the name of their rally. An old man saluted the soldiers who belong to Maj. Gen. Ali Mohsin al-Ahmar, a long-time ally of Mr. Saleh who abandoned the president this week and directed his troops to protect the antigovernment demonstrators.

“Our hope is always growing. Everyday we see an increasingly better future,” said Mohamed al-Sharafi, a son of a sheik from Hadramawt in the southeast. ”It is a confirmed thing that Saleh will leave.”

He went on to say: “The expectation that there is going to be a civil war comes from the government. It is for sure that there will not be a civil war because the north and the south have never been united as they have now.”

His friend, a northerner, kissed him on the cheek after he said that. “The Libyan scenario will not happen here.”

Mr. Saleh spoke Wednesday night with General Ahmar, the country’s most powerful military leader. General Ahmar also spoke on television on Thursday and said he had no interest in political power. “Military rule in the Arab world is outdated,” he declared.

Some reports suggested that both men might step down in a matter of days or weeks to make way for a transitional government and the writing of a new constitution. But one senior American official who was following events in Yemen closely said the immense complexity of Yemen’s tribal society, and Mr. Saleh’s history of brinkmanship, argued for caution.

“The general assumption is that his days are numbered,” said the official, who was not authorized to speak on the record. “But he seems determined to decide the number himself.” The official cautioned that the discussions about Mr. Saleh’s exit are “not just talks in a room” but negotiations involving representatives of 20 or more Yemeni factions and interest groups, often through intermediaries.

According to several accounts, the talks are being closely monitored by representatives of Saudi Arabia, Yemen’s wealthy northern neighbor, and the United States Embassy, which has relied on Mr. Saleh as an ally against the Qaeda branch in Yemen.

“We want to express support for a transition and concern about our security issues,” the American official said. “But we don’t want to take sides.”

Another important tribal leader threw his support to the antigovernment movement on Thursday, adding to the pressure on Mr. Saleh.

Sheik Sinan Abu Lahoum, a leader in the important Bakil tribal confederation, announced his position via a telephone call to the antigovernment sit-in. Mr. Abu Lahoum, who is in the United States for health reasons, said “my age and my health does not permit me to participate with the youth” and urged all Yemenis to participate in the revolution for the sake of the country.

The announcement followed that of the influential tribal leader Sheik Sadeq al-Ahmar, who heads the Hashid confederation, the tribal confederation to which the president belongs.

The raft of desertions accelerated after last Friday’s bloody rally. Analysts said the defections were compelled by the taboo in Yemeni tribal culture against killing innocent, unarmed civilians.

Yassin Saeed Noman, the head of the opposition political coalition, said in an interview that Mr. Saleh “wants a peaceful transfer of power.” But the opposition has rejected Mr. Saleh’s offer to step down at year’s end, and Mr. Noman said no transition should leave the president in power more than “one or two months.”

Mr. Noman, who has been widely discussed as a possible prime minister in an interim government, said the terms of Mr. Saleh’s departure were no longer up to the political opposition. “It depends on people in the streets,” he said.

Meanwhile, there were reports of minor clashes around the country between loyalist military forces and those following General Ahmar. In Jawf, a northern province on Yemen’s border with Saudi Arabia known for being home to both Houthi rebels and Qaeda militants, local reports have said that all government officials have been forced out of the province. A tribal leader said a popular committee was now running all security and administrative duties.

The office of the Arab satellite news station Al Jazeera was closed Wednesday in Sana when the Information Ministry announced it would suspend the channel’s permit, according to Khaled al-Hammadi, a producer for Al Jazeera.

“I think they want to do something important during the upcoming few days,” he said by phone. “For that they want to close all the media.”

On Wednesday morning, the Yemeni government issued a statement urging “foreign media to exercise maximum accuracy as to what they report and to be professional while covering the situation in Yemen.”