Supporters of ousted Egyptian president Mohammed Morsi have defied threats of removal from their sit-in protest in Cairo, despite the deaths of dozens in clashes with security forces.
Speakers from the pro-Morsi Muslim Brotherhood addressed protesters overnight, saying they would not back down from their demands.
They want Mr Morsi - removed from power by the army on 3 July - reinstated.
But the interior minister has warned them they will "soon" be dispersed.
Meanwhile, the US has expressed deep concern at the bloodshed - the worst since Mr Morsi was ousted.
US Secretary of State John Kerry condemned the violence and called on the Egyptian authorities to "respect the right of peaceful assembly and freedom of expression".
Muslim Brotherhood spokesman Gehad el-Haddad told the BBC that "hundreds and thousands of men, women and children" were engaged in the peaceful protest around the Rabaa al-Adawiya mosque.
He said: "Regardless of what happens to the president, we will continue our protest. Our numbers are increasing every day. Citizens are recognising the tyranny and the long-term danger of the military coup".
The BBC's Yasmine Abu Khadra, at the scene in Cairo, says it is now quiet there although the camp has set up its own tight security.
Overnight Muslim Brotherhood leaders delivered passionate speeches to raise the morale of the crowd, our correspondent adds.
Their message was that security forces had carried out the killing on Saturday because they felt threatened by the sit-in. The speakers said the crowd should not be afraid as the protest was for a just cause.
The health ministry puts the death toll from the clashes on Saturday at 78, although doctors estimated that more than 100 people were killed.
Mr Haddad said three types of groups were to blame - "badly dressed thugs, police in three types of uniform and plain-clothed police".
He said the protesters would continue to demand Mr Morsi's reinstatement, adding: "It may take weeks, months, more than a year - we will still hold our ground."
Interior Minister Mohammed Ibrahim told the supporters to "come to their senses" and go home.
He said lawsuits filed by residents near a mosque provided legal cover for the clearance.
The government has denied that security forces fired live rounds on Saturday, saying only tear gas was used.
But the BBC's Quentin Sommerville in Cairo says this appears to be untrue given the severity and number of injuries.
Two leading figures who backed the army's removal of Mr Morsi have condemned the killings.
The Grand Imam of Al-Azhar mosque - the highest Sunni Muslim authority in Egypt - has called for an investigation, while the vice-president of the interim government, Mohamed ElBaradei, said that excessive force had been used.
Saturday's clashes appear to have begun after some of the Morsi supporters tried to extend the barricades around their protest site, and the security forces responded.
Medics at a nearby field hospital told the BBC they believed about 70% of the casualties were caused by live fire - with many of the victims hit in the chest or head by snipers firing from rooftops.
As confrontations were unfolding in Cairo, security forces killed 10 militants and captured 20 others in the Sinai peninsula, state-run Mena news agency said.
Militants have stepped up deadly attacks in the Sinai in recent weeks.
The army removed Mr Morsi, Egypt's first democratically elected president, after mass protests against his rule. Last week it called on supporters to take to the streets to give its action a mandate.
Tens of thousands responded by flooding to Cairo's Tahrir Square on Friday night.
Mr Morsi has been formally remanded in custody at an undisclosed location for an initial 15-day period, according to a judicial order.
He has been accused of the "premeditated murder of some prisoners, officers and soldiers" when he and several Muslim Brotherhood leaders were freed during a breakout at a Cairo prison in January 2011.
He is alleged to have plotted attacks on jails in the uprising that overthrew President Hosni Mubarak.
Mr Morsi is also accused of conspiring with the Palestinian militant group Hamas, which governs the Gaza Strip and has strong links with the Muslim Brotherhood.