Cairo: Egypt's powerful Muslim Brotherhood and the secular opposition banded together Sunday around a prominent government critic to negotiate for forces seeking the fall of President Hosni Mubarak, as the army struggled to hold a capital seized by fears of chaos and buoyed by euphoria that three decades of Mr. Mubarak's rule may be coming to an end.
The announcement that the critic, Mohamed ElBaradei, would represent a loosely unified opposition reconfigured the struggle between Mr. Mubarak's government and a six-day-old uprising bent on driving him and his party from power.
Though lacking deep support on his own, Dr. ElBaradei, a Nobel laureate and diplomat, could serve as a consensus figure for a movement that has struggled to articulate a program for a potential transition. It suggested, too, that the opposition was aware of the uprising's image abroad, putting forth a candidate who might be more acceptable to the West than beloved in Egypt.
In scenes as tumultuous as any since the uprising began, Dr. ElBaradei defied a government curfew and joined thousands of protesters in Liberation Square, a downtown landmark that has become the epicenter of the uprising and a platform, writ small, for the frustrations, ambitions and resurgent pride of a generation claiming the country's mantle.
"Today we are proud of Egyptians," Dr. ElBaradei told throngs who surged toward him in a square festooned with banners calling for Mr. Mubarak's fall. "We have restored our rights, restored our freedom, and what we have begun cannot be reversed."
Dr. ElBaradei declared it a "new era," and as night fell there were few in Egypt who seemed to disagree.
Dr. ElBaradei also criticized the Obama administration, as Secretary of State Hillary Rodham Clinton delivered the message via Sunday news programs in Washington that Mr. Mubarak should create an "orderly transition" to a more politically open Egypt, while she refrained from calling on him to resign. That approach, Dr. ElBaradei said, was "a failed policy" eroding American credibility.
"It's better for President Obama not to appear that he is the last one to say to President Mubarak, it's time for you to go," Dr. ElBaradei said.
The tumult Sunday seemed perched between two deepening narratives: a vision of anarchy offered by the government, and echoed by Egyptians fearing chaos, against the perspective of protesters and many others that the uprising had become what they called "a popular revolution."
The military, Egypt's most powerful institution and one embedded deeply in all aspects of life here, reinforced parts of the capital Sunday. It gathered as many as 100 tanks and armored carriers at the Tomb of the Unknown Soldier, the site of President Anwar el-Sadat's assassination in 1981, which brought Mr. Mubarak to power. The Interior Ministry announced it would again deploy once-ubiquitous police forces -- despised by many as the symbol of the daily humiliations of Mr. Mubarak's government -- across the country, except in Liberation Square.
In a collapse of authority, the police withdrew from major cities on Saturday, giving free rein to gangs that stole and burned cars, looted shops and ransacked a fashionable mall, where dismembered mannequins for conservative Islamic dress were strewn over broken glass and puddles of water. Thousands of inmates poured out of four prisons, including the country's most notorious, Abu Zaabal and Wadi Natroun. Checkpoints run by the military and neighborhood groups, sometimes spaced just a block apart, proliferated across Cairo and other cities.
Many have darkly suggested that the government was behind the collapse of authority as a way to justify a crackdown or discredit protesters' calls for change.
"Egypt challenges anarchy," a government-owned newspaper declared Sunday.
"A Conspiracy by Security to Support the Scenario of Chaos," replied an independent newspaper in a headline that shared space at a downtown kiosk.
The United States said it was organizing flights to evacuate its citizens on Monday, and the American Embassy urged all Americans to "consider leaving as soon as they can safely do so," in a statement that underlined a deep sense of pessimism among Egypt's allies over Mr. Mubarak's fate.
Turkey, a major power in the region, said it was sending three flights to evacuate 750 of its citizens from Cairo and Alexandria.
"We're worried about the chaos, sure," said Selma al-Tarzi, 33, a film director who had joined friends in Liberation Square. "But everyone is aware the chaos is generated by the government. The revolution is not generating the chaos."
Still, driven by instances of looting -- and rumors fed by Egyptian television's unrelenting coverage of lawlessness -- it was clear that many feared the menace could worsen, and possibly undermine the protesters' demands.
"At first the words were right," said Abu Sayyid al-Sayyid, a driver. "The protests were peaceful -- freedom, jobs and all that. But then the looting came and the thugs and thieves with it. Someone has to step in before there's nothing left to step into."
For a government that long celebrated the mantra of Arab strongmen -- security and stability -- Mr. Mubarak and his officials seemed to stumble in formulating a response to the most serious challenge to his rule. Mr. Mubarak appeared on state television on Sunday in a meeting with military chiefs in what was portrayed as business as usual. Through the day, the station broadcast pledges of fealty from caller after caller.
"Behind you are 80 million people, saying yes to Mubarak!" one declared.
That was the rarest of comments across Cairo, though, as anger grew at what residents described as treason and betrayal on the part of a reeling state.
For two days, clashes raged at Abu Zaabal, the prison north of Cairo, and officials said the police had killed at least 12 inmates there before abandoning it. On Sunday, scores of people passed in and out of the colonnaded entrance, hauling boxes and furniture through a black iron gate. Two army tanks parked nearby declined to intervene.
The Muslim Brotherhood said 34 of its members walked out of Wadi Natroun, on the road to Alexandria, after guards abandoned their posts. All had been arrested before dawn Friday, the biggest day of the protests.
"The prisoners themselves freed us from the gang who kidnapped us, this government that has become a gang," said Essam al-Arian, one of the Brotherhood's leaders, who had been among those held.
Since the uprising began last week, the Brotherhood has taken part in the protests but shied away from a leadership role, though that appeared to change Sunday. Mohammed el-Beltagui, a key Brotherhood leader and former Parliament member, said an alliance of the protest's more youthful leaders and older opposition figures had met again in an attempt to assemble a more unified front with a joint committee.
It included Dr. ElBaradei, along with other prominent figures like Ayman Nour and Osama al-Ghazali Harb, who have struggled to build a popular following. By far, the Brotherhood represents the most powerful force, but Mr. Beltagui and another Brotherhood official, Mohamed el-Katatni, said the group understood the implications of seeking leadership in a country still deeply divided over its religious program.
"We're supporting ElBaradei to lead the path to change," Mr. Beltagui said as he joined him in Liberation Square. "The Brotherhood realizes the sensitivities, especially in the West, towards the Islamists, and we're not keen to be at the forefront."
"We're trying to build a democratic arena before we start playing in it," he said.
Whether Dr. ElBaradei can emerge as that consensus figure remained unclear. He won the Nobel Peace Prize in 2005 for his work leading the United Nations nuclear watchdog, the International Atomic Energy Agency.
Even in Liberation Square, the crowd's reaction to Dr. ElBaradei was mixed -- some were sympathetic but many more were reserved in their support for a man who has spent much time abroad.
One Brotherhood supporter, Mohammed Fayed, an engineer, said that even if Dr. ElBaradei could replace Mr. Mubarak, he should stay no longer than a year: "ElBaradei doesn't live here and doesn't know us. We need a leader who can understand Egyptians."
Whatever his success, the army, long an institution shielded from criticism in the state media, was still the fulcrum of events, with a growing recognition that it would probably play the pivotal role in shaping the outcome.
In a show of authority, Mr. Mubarak was shown meeting with Defense Minister Mohammed Tantawi and Omar Suleiman, his right-hand man and the country's intelligence chief, whom he appointed as vice president on Saturday. In slogans and actions, protesters cultivated the military, too, in a bid to turn it to their side.
Military helicopters circled Liberation Square through the day, and jets roared across a late afternoon sky. But the army took no steps against the protesters, who cheered as the helicopters passed overhead. In an unprecedented scene, some of them lofted a captain in uniform on their shoulders, marching him through a square suffused with demonstrators that cut across Egypt's entrenched lines of class and religious devotion.
In contrast to the apprehension elsewhere in Cairo, a carnival atmosphere descended on the square, where vendors offered Egyptian dishes at discount prices and protesters posed for pictures beside tanks scrawled with slogans like, "30 years of humiliation and poverty."
"The people and the army are one hand!" they shouted.
Across the capital, youths and some older men guarded their own neighborhoods, sometimes posting themselves at each block and alley. Several said they were in contact with the military, as well as with each other, and many residents expressed pride in the success that they had in securing their property from the threat of looters and thieves.
The sentiments captured what has become a powerful theme these days in Cairo: that Egyptians again were taking control of their destiny, against the odds.
"We know each other, we stand by each other and people respect what we're doing," said Ramadan Farghal, who headed one self-defense group in the poorer neighborhood of Bassateen. "This is the Egyptian people. We used to be one hand."