Protesters laid siege to Egypt's Interior Ministry on Friday, extending a rally against the military-led government into a second day in a show of anger triggered by the deaths of 74 people in the country's worst football disaster.
In separate clashes in the city of Suez, two protesters were killed as police used live rounds to hold back crowds trying to break into a police station, witnesses said.
Demonstrations erupted in Egypt this week following deaths at a football stadium in Port Said as the football incident turned quickly into a political crisis. Protesters hold the military-led authorities responsible for the bloodshed.
In Cairo, several thousand protesters remained in the streets around the ministry as night fell. The only vehicles in the usually congested downtown area were largely ambulances that ferried away casualties from clashes with police.
Underlining the tension, ambulances had to intervene to extract riot police whose truck took a wrong turn into a street full of protesters, a Reuters witness said.
Protesters surrounded the vehicle for at least 45 minutes, rocking it while the police were inside. Some of the demonstrators then formed a human corridor to help them escape.
Close to 400 people were wounded in confrontations that erupted late on Thursday, the Health Ministry said, many of them suffering the effects of inhaling tear gas fired by riot police who the Interior Ministry said were protecting the building.
Rocks thrown by protesters were strewn across streets that two months ago witnessed violent clashes between police and activists who see the Interior Ministry as an unreformed vestige of former President Hosni Mubarak's rule.
"We are not going to leave this time," said Sami Adel, a 23-year-old member of the ultras, a group of football fans known for confronting police. They have regularly been on the front lines of clashes with security forces over the last year.
Security forces fired tear gas into the night to drive back protesters, who then regrouped ready for more. "The crimes committed against the revolutionary forces will not stop the revolution or scare the revolutionaries," said a pamphlet printed in the name of the ultras.
In Suez, witnesses said fighting broke out at a local police station in the early hours of Friday. "We received two corpses of protesters shot dead by live ammunition," said a doctor at a morgue where the bodies were kept.
A witness said: "Protesters are trying to break into the Suez police station and police are now firing live ammunition."
The football stadium deaths have heaped new criticism on the military council, which has governed Egypt since Mubarak stepped down a year ago in the face of mass protests. Critics regard them as part of his administration and an obstacle to change.
The army leadership, in turn, has presented itself as the guardian of the 25 January revolution. It has promised to hand power to an elected president by the end of June.
Interior minister blames fans
At least 1,000 people were injured in the football violence when fans invaded the pitch after local Port Said team Masry beat Cairo-based Ahly, the most successful club in Africa.
Hundreds of Masry supporters surged across the pitch to the visitors' end and panicked Ahly fans dashed for the exit. But the steel doors were bolted shut and dozens were crushed to death in the stampede, witnesses said.
The cause of the violence has been the focus of intense speculation. Some believe it was triggered by unknown provocateurs working for remnants of the Mubarak administration who are seeking to sabotage the transition to democracy.
Interior Minister Mohamed Ibrahim said the fans started it.
"The events started with provocations between the Ahly and Masry crowds, then insults, until it ended up with those sorrowful events," he told the Egyptian TV station CBC during a telephone interview.
Ibrahim was widely blamed for the deaths during an emergency parliamentary session on Thursday. MPs, including the Islamists who control some 70 percent of the chamber, called for him to be held to account and accused him of negligence.
Safwat Zayat, an analyst, said the incident had done further damage to the image of the ruling military council. "The current events push in the direction of speeding up the transfer of power to civilians," Zayat told Reuters.
Field Marshal Hussein Tantawi, the head of the military council, responded to the deaths by vowing that Egypt would remain stable. "We have a roadmap to transfer power to elected civilians," he said in broadcast remarks.