Supporters of ousted Egyptian president Mohamed Morsi announced new demonstrations on Sunday as the country grew increasingly polarised and the death toll in four days of violence topped 750.
A day earlier, police stormed a Cairo mosque where Morsi loyalists had holed up, after trading fire with gunmen inside its minaret.
The call for fresh demonstrations looked set to test the so-called Anti-Coup Alliance of Morsi loyalists, which failed to hold mass rallies on Saturday, but has insisted that protests will continue.
The group announced two major rallies in east and south Cairo following afternoon prayers at 1400 GMT.
Ahead of the rallies, some semblance of normality returned to the streets of the capital, which is under a night-time curfew and has been unusually quiet in recent days.
Traffic was almost at normal levels, and banks and shops opened their doors cautiously after four days of violence since Wednesday, when police cleared two pro-Morsi protest camps.
At least 578 people died across the country in clashes following the operation, and the government said another 173 people were killed between Friday and Saturday, bringing the toll in just four days to more than 750.
The violence has shocked the international community, but Egypt's government -- installed by the army after Morsi's July 3 ouster -- has fiercely defended its actions.
Egypt has found itself divided as never before in recent history, with Morsi's many opponents stridently condemning his supporters as "terrorists."
On Saturday, as police dragged protesters from the Fath mosque in Cairo, angry bystanders tried to assault them, cheering as they were packed into police cars.
The area had turned briefly into a battleground, with security forces trading fire with gunmen inside the mosque, leaving bullet holes in its minaret.
The interior ministry said 385 people inside the mosque had been arrested.
There was renewed speculation that the government would move to ban Morsi's Muslim Brotherhood, although the military-installed interim presidency appeared to dismiss the idea.
"We're not into the effort of dissolving anyone or preventing anyone" from taking part in politics, presidential adviser Mustafa Hegazy insisted on Saturday.
According to an AFP tally, more than 1,000 people have been killed since mass demonstrations against Morsi at the end of June, among them a son of the Brotherhood's supreme guide on Friday.
Violence has also continued in the Sinai Peninsula, where militants carried out attacks overnight in the northern city of El Arish, killing a civilian, two soldiers and a policeman, security sources said.
The interim government has defended the crackdown. "We had to take measures to confront terror against the people," foreign minister Nabil Fahmy said.
Hegazy insisted the security forces had acted with "a huge amount of self-restraint and self-control".
State television has for days broadcast under a banner reading in English "Egypt fighting terrorism."
The imam of Cairo's Al-Azhar, one of Sunni Islam's key institutions, called for "all Egyptians to take part in reconciliation."
But international criticism has mounted, with European Union leaders saying Sunday that they would review ties with Egypt's army and government if the violence continues.
"The EU will urgently review in the coming days its relations with Egypt," EU leaders Herman Van Rompuy and Jose Manuel Barroso said.
German Foreign Minister Guido Westerwelle said on Saturday that he and his Qatari counterpart were "deeply distressed by the ongoing and brutal violence in Egypt."
He urged the two sides to resume dialogue, citing the "danger of civil war."
Late Saturday, British Foreign Secretary William Hague called his Egyptian counterpart to express London's "condemnation of all acts of violence, whether disproportionate use of force by the security forces or violent actions by some demonstrators."
He also described as "unacceptable" a string of attacks against churches and Christian properties blamed on Morsi's supporters.
UN chief Ban Ki-moon urged an end to violent protests and condemned "excessive use of force" in handling them.
The Vatican said Pope Francis was following events with "mounting concern."
The United States has announced the cancellation of its biannual military exercise with Egypt, but stopped short of suspending $1.3 billion in annual aid.
The US embassy in Cairo stayed closed on Sunday, a working day in Egypt, citing the possibility of fresh demonstrations nearby.
But the international response has not been uniformly critical. Saudi Arabia and Jordan said they backed Egypt in its fight against "terrorism".