Egypt's state television reported that Cairo's Tahrir Square and the Ittihadeya presidential palace's vicinity will be sealed off until Saturday 4 p.m.
The state imposed a curfew from 7 p.m. every Friday because of the Muslim Brotherhood's continuing protests since former President Mohamed Mursi was removed from power in July.
Groups of Brotherhood supporters marched on Friday afternoon to Tahrir Square, which has been completely sealed since morning, and to Rabaa al-Adaweya Square in Nasr City.