Egypt's army-backed government has ordered police to take all necessary measures to end sit-ins by supporters of ousted Islamist President Mohammed Morsi in the capital Cairo.
Muslim Brotherhood supporters have been staging sit-ins since Mr Morsi was removed from power on 3 July.
They have defied previous threats of removal from their sit-in protests, despite deadly clashes with security forces, the BBC reports.
A government official said in a televised statement that the rallies were a national security threat.
The main protest sit-in is at a square near the Rabaa al-Adawiya mosque in the capital's north-east, where clashes erupted on Saturday in which some 70 people were killed, and in Nahda Square near the main campus of Cairo University.
A Muslim Brotherhood spokesman told the BBC his supporters had no option but to stay put, saying the decision to clear the camps had been taken by a gang that had taken over the state and was trying to cheat the people of their democratic rights.
The ousted leader has been formally remanded in custody at an undisclosed location, according to a judicial order.
He had received no official visitors until Tuesday, when he met EU foreign policy chief Catherine Ashton who said he was "well".
An African Union delegation confirmed on Wednesday that it had met Mr Morsi, who has not been seen in public since being removed from office.