Egypt has declared a month-long state of emergency after scores of people were killed when security forces stormed two protest camps in Cairo.
Thousands of supporters of deposed President Mohammed Morsi and his Muslim Brotherhood had staged the sit-ins.
Police have arrested key Brotherhood members and taken control of the camps. The government says 149 people were killed in the operation.
The US condemned the emergency law and appealed for calm.
The Muslim Brotherhood says more than 2,000 people died in Wednesday's violence.
The state of emergency is scheduled to last for a month, and imposes a curfew in Cairo and several other provinces between 19:00 local time (17:00 GMT) and 06:00.
The measure was taken because the "security and order of the nation face danger due to deliberate sabotage, and attacks on public and private buildings and the loss of life by extremist groups," the presidency said in a statement.
Vice-President Mohammed ElBaradei has announced his resignation from the interim government in the wake of the violence.
"I cannot continue in shouldering the responsibility for decisions I do not agree with and I fear their consequences. I cannot shoulder the responsibility for a single drop of blood," he said in a statement.
Armoured bulldozers moved into the two protest camps shortly after dawn on Wednesday morning.
Large plumes of smoke rose over parts of the city as the operation began. Security forces fired tear gas canisters as helicopters circled above.
The smaller camp in Nahda Square was cleared relatively quickly, but clashes raged for most of the day around the main camp near Cairo's Rabaa al-Adawiya mosque.
Egyptian television said that by evening the security forces had finally seized full control of the site, and were allowing surviving protesters to leave.
But several Muslim Brotherhood leaders were reportedly detained, including Essam El-Erian and Mohamed El-Beltagy, whose 17-year-old daughter was apparently killed.
Most of the dead are thought to be Morsi supporters, but members of the security forces were also killed.
A cameraman working for Sky News, Mick Deane, was also killed, as was a reporter for Gulf News, Habiba Ahmed Abd Elaziz. She was not working at the time.
There are also reports of unrest elsewhere in Egypt.
- About 35 people have died in clashes in the province of Fayoum, south of Cairo, Reuters news agency says.
- At least five people have been killed in the province of Suez, according to the health ministry.
- Clashes have also been reported in the northern provinces of Alexandria and Beheira, and the central provinces of Assiut and Menya.
- State news agency Mena says three churches have been attacked, one in the city of Sohag which has a large number of Coptic Christian residents.
Supporters of Mr Morsi have been staging street protests since he was ousted on 3 July.
The protesters - many of whom are members of Mr Morsi's Muslim Brotherhood movement - want him to be reinstated.
Mr Morsi was Egypt's first democratically elected president, narrowly winning the presidential vote in June 2012 after the overthrow of Hosni Mubarak.
Mr Morsi is currently in custody at an undisclosed location, and has been accused of the "premeditated murder of some prisoners, officers and soldiers" during a prison breakout in 2011.
Call for restraint
There has been strong international reaction to the storming of the camps.
US Secretary of State John Kerry said the events were "deplorable" and "a real blow to reconciliation efforts". He said the unrest "ran counter to Egyptians' aspirations to peace and democracy."
"Violence is simply not a solution in Egypt," he said.
"It will not create a roadmap for Egypt's future. violence and continued political polarisation will further tear the Egyptian economy apart."
A statement issued on behalf of EU foreign policy chief Catherine Ashton said: "We reiterate that violence won't lead to any solution and we urge the Egyptian authorities to proceed with utmost restraint."
Turkish PM Recep Tayyip Erdogan described the result of the camp clearances as a massacre, accused other countries of paving the way for the violence by staying silent, and called for the UN and the Arab League to act immediately.
UK Foreign Secretary William Hague also condemned the use of force.