An Egyptian government building was set on fire on Sunday as protests disrupted the heart of Cairo for a fourth day and public figures demanded a faster transition to civilian rule.
It was unclear who was behind the attack, shown by Egyptian television after midnight, with the state news agency blaming unknown arsonists.
The building is near the Cairo headquarters of the Interior Ministry, the focus of the latest wave of protests against the army-led government triggered by the deaths of 74 people in violence at a soccer stadium in Port Said on Wednesday.
Seven people have been killed in protests around the Interior Ministry since Thursday, with another five killed in demonstrations in Suez, a city east of Cairo.
Protesters and security forces clashed again on Saturday in Cairo despite efforts by some activists to halt the violence.
Youths threw rocks at police who fired tear gas to disperse them in bouts of violence throughout the day. The Interior Ministry said the police were trying to protect the building.
Protesters hold the Interior Ministry responsible for the deaths in Port Said. There has been intense speculation about the cause of the soccer stadium disaster, Egypt's worst.
Some believe remnants of the Mubarak regime triggered violence that caused a stampede, part of a plot to create chaos to reassert their influence. The interior minister has blamed the incident on provocations by rival fans.
The Port Said incident has heightened criticism of the Supreme Council of the Armed Forces, due to hand power to a new president at the end of June according to its own timetable.
Responding to one of Egypt's bloodiest weeks since Mubarak was toppled, the council said the country was going through the most important and dangerous period in its history.
A civilian council set up to advise the generals recommended on Saturday they bring forward preparations for presidential elections, a view echoed by a leading member of the Muslim Brotherhood, the biggest party in parliament.
In view of the seriousness of the events, the carnage that happened, we cannot be silent, we cannot wait, said Mona Makram Ebeid, a council member. It's a revolutionary plea.
The advisory council will consider halting its meetings if the military council does not respond, Sherif Zahran, another member of the body, told Reuters.
Formal nominations for the presidency should be accepted starting February 23, according to the recommendation, nearly two months sooner than the April 15 date previously announced.
That could lead to an election as soon as April or May. The existing timetable states the generals will hand power to a president by the end of June. Officials had indicated the election would happen just before then.
Essam el-Erian, the deputy head of the Brotherhood's Freedom and Justice Party, told Reuters the presidential election could be held in May, shaving a month off the interim period.
(Additional reporting by Tom Perry and Marwa Awad; Writing by Tom Perry Editing by Maria Golovnina)