Egyptian Islamists have called for a fresh round of demonstrations on Sunday, a day after security forces ended a tense standoff with protesters in a Cairo mosque.
On Saturday, security forces took control of the al-Fath mosque, where many supporters of ousted President Mohamed Morsi sought refuge after Friday's bloody "Day of Rage."
Egypt's interim government has accused Mr. Morsi's Muslim Brotherhood of provoking the violence that has killed more than 700 people since Wednesday. The Brotherhood says the death toll is much higher.
Prime Minister Hazem el-Bablawi has proposed dissolving the Muslim Brotherhood, a move that would force the group underground and could usher in mass arrests of its members countrywide.
Egypt's state news agency says some 250 Brotherhood supporters are under investigation in relation to the recent turmoil.
The deadliest day was Friday, when clashes in Cairo and other cities left 173 people dead and more than 1,000 injured, according to the government.
Officials say among those killed Friday was a son of Mohamed Badie, chief of the Muslim Brotherhood movement.
A government spokesman said 57 police officers were killed Friday.
Authorities say the brother of Egyptian-born al-Qaida leader Ayman al-Zawahiri, Mohamed al-Zawahiri has been detained during the unrest, along with more than 1,000 other people connected to the Brotherhood.
In a statement late Saturday, U.N. Secretary-General Ban Ki-moon urged an end to the violent protests and cited an "excessive use of force" in handling them. He said preventing more deaths should be the Egyptians' top priority at this time.