More than 1,000 protesters, who were being joined by a stream of others, gathered in central Cairo on Sunday demanding President Hosni Mubarak step down and dismissing his appointment of a vice president.
Meanhwile, the Egyptian army was guarding the deserted Interior Ministry headquarters in central Cairo on Sunday after officials were evacuated, an officer said.
"We secured the Interior Ministry this morning and evacuated state security personnel. The ministry is empty," an army officer who did not want to be named told Reuters at the site. "We're here for as long as it takes."
Two armoured trucks and a tank stood guard outside. State security fought with protesters trying to attack the building on Saturday night.
"Hosni Mubarak, Omar Suleiman, both of you are agents of the Americans," shouted protesters, referring to the appointment of intelligence chief Suleiman as a vice president, the first time Mubarak has appointed a deputy in 30 years of office.
It was the position Mubarak held before he become president.
"Mubarak, Mubarak, the plane awaits," the demonstrators also chanted.
More than 100 people have been killed in protests that erupted in Egypt over the past week against President Hosni Mubarak's rule.
Egyptians dismiss Mubarak govt changes
"Hosni Mubarak, Omar Suleiman, both of you are agents of the Americans," shouted protesters.