Egyptian protesters chant slogans against the anti-military ruling council during a demonstration following the Muslims weekly Friday prayers, part of nationally organized protests called "The revolution first" at the main Arba'in square in Suez, Egypt Friday, July 8, 2011. (Nasser Nasser/AP)

Tens of thousands of Egyptians gathered Friday in Tahrir Square, the symbol of the uprising that ousted President Hosni Mubarak this year, to protest what they perceive as an unwillingness to prosecute Mubarak-era officials and police responsible for the killing of nearly 900 protesters.

The demonstration, dubbed the “Friday of determination,” was the largest since the revolt in January and February that changed Egypt and inspired other Arab countries to rise up against their autocratic leaders. Egyptians in the square said they had no plans to leave.

Tents were erected in the traffic circle at the square’s center, and stages were built for speakers, reminiscent of the winter days when masses of people refused to leave central Cairo until Mubarak was ousted.

Demonstrations were peaceful Friday, but the past two weeks have been tense, with many Egyptians voicing growing anger over what they consider the slow pace of change under the interim military government and the failure to bring to justice the perpetrators of crimes committed during the 18-day revolution and Mubarak’s 30-year rule.

So far, only one noncommissioned police officer from the Mubarak era has been convicted for the attacks this winter that killed hundreds of unarmed people. The officer was sentenced to death in absentia, and the penalty cannot be enforced. Meanwhile, more than 7,000 civilians have been tried and convicted in military tribunals, prompting an outcry from human rights activists.

Demonstrators have clashed violently with police multiple times in recent days as Mubarak-era ministers were acquitted on corruption charges and police officers in Suez who had been accused of killing protesters were released on bail.

In anticipation of Friday’s protest, Egyptian authorities tried to calm the rage. Interior Minister Mansour el-Essawi promised to reshuffle the ministry that oversees the police and dismiss hundreds of police officers and generals linked to attacks during the uprising.

On Thursday, 25 officials from Mubarak’s government were charged with manslaughter, attempted murder and assault in connection with an organized attack in February in which men charged the crowd in Tahrir Square on horses and camels. The accused include the speakers of both houses of parliament and lawmakers from Mubarak’s National Democratic Party, as well as businesspeople and former cabinet ministers.

But many Egyptians said Friday that those measures are not enough, adding that they are determined to resurrect the revolution. People gathered in the square for the weekly communal noon prayers, bowing and prostrating themselves in unison. “All hands are one hand, we are all one hand,” the imam, or prayer leader, said. He then called for justice to be done.

Volunteers searched those entering the square for weapons, and people chanted, sang and called for justice as vendors sold juice, tea and revolutionary trinkets.

Some had brought hard hats just in case stone-throwing and clashes broke out.

Campaign posters for fledgling political parties fielding candidates in the parliamentary elections scheduled for September were erected throughout the square, urging justice. The Muslim Brotherhood, which has been criticized for being slow to join the revolution and too close to the military leadership, was represented on the largest stage in the square. The sign behind the speakers carried a picture of a noose and jailhouse bars. “Friday of justice and purification,” it read.

Protesters of all ages and ideologies called for the ouster of Field Marshal Mohammed Hussein Tantawi, the head of the Supreme Council of the Armed Forces, which is governing the country during the transition.

“Oh, Tantawi, it’s our army, it’s our army. You will not make us fight each other,” one man shouted into a microphone. “The revolution will never die.”

Next to a yellow and blue tent, Hanan Abdulla, 23, smoked a cigarette.

“I want proper trials against those responsible for the crimes, not only in those 18 days, but for the last 30 years,” she said. “I’ll stay for however long it takes.”

Around her, others echoed those sentiments as they camped out, ready, they said, to sleep in the square for days or weeks until justice was served.

Cafes around the square filled up with people seeking an escape from the sun. Cartoons were displayed showing Mubarak relaxing in a hospital bed with a seaside view and a conversation bubble that read, “I’m really happy here.”

Abdel Rahman Mohammed Badr, 28, a member of the April 6 youth movement, which played an important role in the uprising, passed out fliers with lists of demands.

“We want results. The trust is gone between the Supreme Council of the Armed Forces and the people,” he said.

Just a few blocks from the square, shop owners shook their heads in disgust. Business was slow, and many had shuttered their shops for the day.

Mohammed Abbas, who sells nuts and sweets, said he blamed the continued protests, adding that he wanted things to stabilize, the uncertainty to be over and life to go back to normal.

“This doesn’t have meaning anymore,” he said. “Let the people work. Leave us to attend to our businesses.”

Large-scale protests were also reported for a fourth consecutive day in Suez — where police first killed protesters — and in other cities across Egypt. In Sharm el-Sheikh, a few hundred protesters gathered outside the hospital where Mubarak is being held until his August trial, calling for his immediate removal from the coastal city.

Special correspondent Sulafeh Munzir al-Shami contributed to this report.