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.
A large number of Mohammad Morsi's supporters have been killed in clashes with security forces in Cairo.
The BBC reports that the health ministry puts the death toll from the clashes on Saturday at 78, although doctors estimated that more than 100 people were killed.
The Muslim Brotherhood, which is organising protests demanding Mr Morsi's reinstatement, accused soldiers of shooting to kill.
The government denied this, insisting security forces only used tear gas, not live rounds.
The army ousted Mr Morsi on 3 July. He is now formally accused of murder, relating to a prison breakout in January 2011, and of links to Hamas.
He is also accused of plotting attacks on prisons in the uprising that overthrew President Hosni Mubarak.
The anti-Morsi camp occupied Tahrir Square in support of the army, after General Abdel Fattah al-Sisi urged people to demonstrate to provide a mandate for its intervention.
Morsi supporters continued their sit-in protest at the mosque in the Nasr City area and built a wall to protect themselves.
Early on Saturday, Interior Minister Mohammed Ibrahim vowed to end the sit-in, saying residents had complained about the encampment.
He said the protest would be "brought to an end soon, and in a legal manner" with an order from the prosecutor, although this is yet to happen.
The BBC reports it appears that the clashes began after some Morsi supporters tried to block a road in the area and security forces responded.
The Mena news agency quotes a security official as saying they had been trying to stop fighting between rival sides, and that eight security personnel had been injured.
But a BBC correspondent said many of the casualties had been hit in the chest or head by snipers firing from rooftops.
Interim vice president Mohamed El Baradei said excessive force was used.
The ABC reports the bloodshed is the worst since Mr Morsi was ousted.
United States Defence Secretary Chuck Hagel on Saturday urged restraint in a call with General al-Sisi.
Mr Hagel said steps should be taken to prevent further bloodshed and loss of life.
Secretary of State John Kerry described the situation as a pivotal moment for Egypt. In a statement, he called for the right of peaceful assembly to be respected.