Soldiers baton-charged demonstrators in Cairo's Tahrir Square on Saturday, a day after street clashes killed eight people and wounded more than 300, marring the first free election most Egyptians can remember.
The violence highlights the tensions in Egypt 10 months after a popular revolt toppled President Hosni Mubarak.
The army generals who replaced him have angered some Egyptians by appearing reluctant to give up power. Others back the military as a force for badly needed stability during a transition to democracy.
Protesters fled into side streets to escape the troops in riot gear, who grabbed people and battered them repeatedly even after they had been beaten to the ground, a Reuters journalist said. Shots were fired in the air.
Television footage showed soldiers pulling down protester tents and setting them on fire.
The army assault followed skirmishes between protesters and troops. Some protesters had been throwing stones near fire-brigade vehicles trying to douse a burning building.
The bloodshed follows unrest in which 42 people were killed in the week before Nov. 28, the start of a phased parliamentary poll that is empowering Islamist parties repressed during the 30-year Mubarak era, when elections were routinely rigged.
Voting in the second round of a tortuous election process seen as part of a promised transition from army to civilian rule by July went peacefully on Wednesday and Thursday.
Friday's clashes pitted thousands of demonstrators against soldiers and plainclothes men who were seen at one point hurling rocks from the roof of a parliament building.
The army-appointed prime minister, Kamal al-Ganzouri, blamed the violence on protesters he accused of attacking the cabinet and parliament buildings that security forces had to defend.
I still say we will not confront any peaceful protests with any kind of violence even by words, he said on state television in his first public comments on the disturbances.
I confirm that the army has not used gunfire, he said, reiterating a military statement on Friday.
Ganzouri, 78, said eight people had been killed and 125 of the 303 wounded were in hospital. Thirty security guards outside parliament had been hurt and 18 people had gunshot wounds.
State media gave conflicting accounts of what sparked the violence on Friday. State media cited some people saying a young man went into the parliament compound to retrieve a miskicked football, but was harassed and beaten by police and parliamentary guards.
But they also cited others who said the young man had prompted scuffles by trying to set up camp in the compound.
Among the dead was a senior official of Egypt's Dar al-Iftah, the body that issues Islamic fatwas (edicts).
A new civilian advisory council set up to offer policy guidance to the generals said it would resign should its recommendations on how to solve the crisis not be heeded.
The council announced that it would suspend its meetings until the violence stops. It also asked the army to release all those detained in the trouble and called for prosecution of those responsible and compensation for the victims.
Islamist and liberal politicians decried the army's tactics.
The Muslim Brotherhood, whose party list is leading the election, said in a statement the military must make a clear and quick apology for the crime that has been committed.
Pro-democracy activists have accused the army of trying to clear a sit-in outside the cabinet office that a small number of protesters has maintained since the November violence.
Even if the sit-in was not legal, should it be dispersed with such brutality and barbarity? asked Mohamed ElBaradei, a presidential candidate and former U.N. nuclear watchdog head.
The army council is in charge until a presidential election in June, but parliament will have a popular mandate that the military will find hard to ignore as it oversees the transition.
The council wants to spoil the elections. They don't want a parliament that has popular legitimacy, unlike them, and would challenge their authority, said Shadi Fawzy, a pro-democracy activist. I don't believe they will hand over power in June.
(Additional reporting by Ashraf Fahim and Edmund Blair; Writing by Alistair Lyon; Editing by Angus MacSwan)