The demonstration, billed as a "Day of Victory and Continuation," came a day after three senior government officials and a wealthy industrialist who were close to Mubarak and were members of the ruling party were arrested on suspicion of corruption, money laundering and the misuse of public funds. Prosecutors are investigating the allegations, state television reported.
The arrests were a clear message from the military leaders now running Egypt that they intend to crack down on corruption among those associated with Mubarak's government, which the demonstrators say stole state resources and instituted a system of crony capitalism that widened the gap between rich and poor.
Those detained, according to state television, were Habib al-Adli, who as interior minister commanded the brutal police and paramilitary security forces; former housing minister Ahmed Maghrabi; former tourism minister Zuhair Garana; and Ahmed Ezz, a steel magnate and a senior leader in the ruling party.
Ezz is widely reviled in Egypt. Hosni Mubarak's son Gamal brought him into the National Democratic Party (NDP) in 2000, and Ezz rose quickly through the ranks. He reportedly controls 60 percent of the steel industry and was the right-hand man of Gamal Mubarak, whose responsibility it was to modernize the government's operations and open markets.
Ezz is accused of orchestrating parliamentary elections last year that were rigged to allow the ruling party to sweep the vote, said Mohamed Abdellah, a former lawmaker and longtime prominent member of the NDP. Ezz not only monopolized businesses but monopolized the party, Abdellah added.
"For years, he centralized all the political power in his hands," Abdellah said. "He chose the candidates and gave direction to the party."
Adli, the former interior minister, is seen as representing the brutality of the state security services and police. During the 18-day uprising that began Jan. 25, police fired tear gas, rubber bullets and sometimes live ammunition at the demonstrators.
Abdellah said Adli cut off access to the Internet for days and was responsible for the attacks on protesters. "He's an arrogant man," Abdellah said.
The detained officials denied the allegations against them, according to state media.
In Tahrir, or Liberation, Square on Friday, a troupe of men wearing black T-shirts danced and sang in celebration of the arrests. Makeshift placards and banners held up by the crowd proclaimed the end of Hosni Mubarak's 30-year rule and called on the generals to pursue all corrupt officials, revise the constitution and make Egypt a democracy.
"Our demands are clear as the sun," read a sign held by Marway el-Rawy, a 23-year-old woman.
Yusuf al-Qaradawi, a renowned Islamic scholar, presided over Friday prayers in the square, the heart of the revolt.
He called on the military to dismantle the current government and then said that the square should be renamed "Martyrs' Square" for the more than 330 people who were killed there.
Two men in the crowd, wearing beards and long robes, said they had traveled from Mansour, 100 miles to the northeast, to remind the Supreme Council for the Armed Forces that all the protesters' demands have not been met.
A man wept as he stared at a portrait of a person killed during the uprising. Then he kissed the poster.
"We're here to send a message to the military that we can come out at any time if they don't deliver," said Mohammed Moussa, 25.
Among the crowd were sweat-shirt-wearing teenagers, small children in jackets emblazoned with Harley-Davidson logos, women in jeans or full-length black abayas, men in sport coats and men in frayed shirts.
Four men marched holding aloft crescents, the emblem of Islam, with a Christian cross nestled inside. "That is the best sign of all!" a passing taxi driver shouted.
An elderly man, Samir Hossein Sayyed, watched as enormous wreaths were laid honoring the uprising's dead.
"My grandson was martyred," he said. He leaned into clumps of people, repeating his words, near tears. His grandson was only 17, he said. His name was Islam Sayyed, and he died in the square on Jan. 28.
After the gathering, the military's Supreme Council declared continuing strikes illegal. Although Friday's celebration appeared to have been sanctioned by the military, labor protests - from the oil sector to the police force - have not been. The council added that it would not allow the strikes to go on because of "their severe danger to the nation" and would "confront them and take the legal measures needed to protect the nation's security," according to state television.
Special correspondent Muhammad Mansour contributed to this report.