The Egyptian capital Cairo is poised for renewed protests by supporters of ousted President Mohammed Morsi.
They are expected to take place two days after authorities broke up Muslim Brotherhood protest camps in Cairo with the loss of at least 638 lives.
Mr Morsi's supporters plan to converge on central Ramses Square from city mosques after Friday prayers.
A state of emergency is in force and police have been authorised to use live ammunition in self-defence.
BBC journalists in Ramses Square describe the atmosphere as very tense and have been advised by the crowd to leave as the area is too dangerous to stay.