Egyptian riot police deployed on Saturday near the presidential palace after a night of clashes between security forces and petrol-bomb throwing protesters that killed one man and injured nearly 100.
The 23-year-old died of a gunshot wound as police used birdshot and tear gas on demonstrators who targeted the palace in rallies against Islamist President Mohamed Morsi late on Friday, a senior medical official said.
Ninety-one people were also injured, said the official, while the interior ministry reported 15 of its men wounded by birdshot.
Police said they made 20 arrests, and were filmed on television beating and dragging a naked man to an armoured vehicle, outraging Morsi's critics who compared the incident to practices under deposed leader Hosni Mubarak.
The opposition National Salvation Front is to meet later on Saturday to review its strategy after the clashes that erupted following its call for people to take to the streets.
The NSF called for Interior Minister Mohammed Ibrahim to resign over the beating of the naked man, which triggered an outpouring of condemnation on social media websites.
"The horrible and degrading images showing the central security officers and police beating and dragging a naked man near the presidential palace should lead to the interior minister's immediate resignation," NSF spokesman Khaled Dawoud said.
Ibrahim has ordered a probe to "hold accountable" the policemen who beat the man, his office said.
On Saturday, there was no sign of any protesters, and streets in the area around the presidential palace reopened to traffic, though they were littered with debris.
The smell of tear gas still lingered near the palace, its outer wall scrawled with graffiti including "Topple the regime" and "Freedom."
In Cairo's iconic Tahrir Square, the situation was also calm after clashes on Friday.
The presidency said security forces would deal with violent protests with "utmost decisiveness" and that it would hold opposition groups found to have incited the clashes "politically accountable."
Morsi's Facebook page said the protesters sparked the violence by trying to break into the palace.
The opposition, which accuses Morsi of betraying the revolution that toppled Mubarak two years ago, distanced itself from the violence and urged demonstrators to exercise "utmost restraint."
But hours before the violence erupted, NSF leader and Nobel Peace laureate Mohamed ElBaradei suggested unrest would persist if Morsi kept sidelining his opponents.
"Writing on wall: violence and chaos will continue until Morsi and co. listen to people's demands: new government, democratic constitution, independent judiciary," he wrote on Twitter.
People took to the streets in a show of opposition to Morsi and his Muslim Brotherhood after deadly unrest swept Egypt last week in the worst violence since Morsi was elected president in June.
The opposition is thought to exert little influence over activists involved in clashes.
"The National Salvation Front represents only itself," said one masked protester outside the palace. "We are satisfied neither with Morsi nor the opposition."
Scores of protesters skirmished with riot police several hundred metres (yards) from Tahrir Square, witnesses said, and two were wounded by birdshot fired by police.
The clashes were less intense than in the past week.
Nearly 60 people have died in the clashes, mostly in Port Said, where violence erupted after 21 residents were sentenced to death a week ago over football-related violence last year.
Thousands of people protested in the Suez Canal city on Friday calling for Morsi's removal, unfazed by a strong military presence, and similar marches took place in the Mediterranean port city of Alexandria.
The NSF joined rival Islamists Thursday in condemning violence and supporting efforts for a national dialogue, while insisting on a unity government and the amendment of the Islamist-drafted constitution, which polarised the nation when it was passed in December.
The crisis has sapped the popularity of Morsi -- who won the June election with a slender majority -- and complicated negotiations for a crucial $4.8-billion IMF loan that could help bail out the teetering economy.