Cairo: The Egyptian military strongly reinforced parts of the capital on Sunday, and black-clad security forces were seen moving through the streets for the first time in a day as a street uprising ran into its sixth day and thousands of protesters again flooded Cairo's city center in defiance of a curfew.
Military jet fighters and helicopters, some bearing the presidential seal, flew low over the center of the city in a show of strength, and soldiers fired shots into the air in an effort to control the crowd. But tens of thousands remained as the sun began to set, chanting defiantly for the ouster of President Hosni Mubarak.
Earlier Sunday, with the situation on the ground still fluid, soldiers erected new roadblocks and turned back cars as thousands of Egyptians on foot filtered back into the city center after the overnight curfew had ended. Around 50 tanks and other armored vehicles rolled into the upmarket suburb of Heliopolis, near the airport and close to Mr. Mubarak's home, and by afternoon, witnesses saw trucks of black-clad security forces, absent from the center of the capital for at least a day, returning.
Adding to public fears about disorder, Interior Ministry officials said prisoners had escaped from four prisons, including two of the country's most notorious, Abu Zaabal and Wadi Natroun.
For two days, clashes had raged at Abu Zaabal, a prison north of Cairo, and officials said the police had killed at least 12 inmates.
The Muslim Brotherhood, Egypt's most powerful opposition, which has taken part in the protests but shied from leadership, said 34 of its members walked out of Wadi Natroun prison after guards abandoned their posts. All 34 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-Iryan, one of the leaders.
In the central Tahrir Square, or Liberation Square, which has become a center of protest, the demonstrators again feted the military as guardians. At one point, crowds hoisted an officer aloft and carried him through the throng chanting: "The people and the army are one hand."
But as the morning wore on, the jubilant tone was tempered by a sense of foreboding.
In another part of Cairo, witnesses reported seeing around 100 tanks and armored personnel carriers gathered in the same parade ground where the former President Anwar al-Sadat, who made the Camp David peace agreement with Israel in 1979, was assassinated in 1981. Mr. Sadat's death propelled Mr. Mubarak, then the vice president, into a position he has never left, steadfastly refusing to name a vice president until now.
Sunday is usually the start of the work week here but banks, schools and the stock market remained closed in a city paralyzed by the uprising, scarred by looting and bracing for further protests. Local residents, armed with sticks and knives, organized into neighborhood protection committees, amid reports that the government was releasing prisoners onto the streets. Some Cairenes said gas stations were running out of fuel and many automated cash machines had either run out of money or had been looted.
The government tightened its vise on information. Security forces raided and closed Al Jazeera's offices in Cairo, forcing it off the satellite most commonly received here and revoking its broadcasting license. The station went back up on alternate satellites within about an hour, but remained invisible locally. Internet connections remained shut down for a third day.
In a statement on Sunday, the American Embassy here said it was telling "U.S. citizens in Egypt who wish to depart that the Department of State is making arrangements to provide transportation to safe-haven locations in Europe." About 90,000 Americans live and work in Egypt.
"Flights to evacuation points will begin departing Egypt on Monday, Jan. 31," the statement said, adding that the Obama administration had authorized the "voluntary repatriation" of American citizens including diplomats' dependents and some employees not dealing with emergencies, meaning they could choose to leave if they wished.
Turkey, a major regional player, said it was sending three flights to evacuate 750 of its citizens from Cairo and Alexandria, a day after Israel flew back the families of its diplomats in Egypt as well as about 40 Israeli citizens who were in Egypt on private business.
France, Britain and Germany issued a rare joint statement urging President Mubarak and the protesters to show restraint. But, like President Obama, they did not call for the ouster of an autocratic leader who has cast himself as a linchpin of Western diplomatic and security interests in the Middle East.
Egypt closed its border with the Palestinian coastal enclave of Gaza, Palestinian authorities said. In a highly unusual development, a diplomat said, Israel authorized Egyptian troops to take up positions in the north of the Sinai peninsula, despite a prohibition on such deployments in the 1979 Camp David peace accord. The diplomat spoke in return for anonymity in light of the sensitivity of the issue.