At least 59 people are reported to have been injured in fresh clashes in Egypt between protesters and security forces near the defence ministry in Cairo.
Security forces used water cannons and tear gas to drive back demonstrators.
A curfew has been imposed from 11pm local time on Friday. The protesters have dispersed and some joined a demonstration in Tahrir Square.
TV pictures showed riot police and military police trying to disperse the crowd by firing water cannons and tear gas.
State television blamed the Muslim Brotherhood for the trouble.
Clashes also happened between protesters and security forces in Alexandria on Friday.
The BBC reports at least 20 people were killed by unidentified assailants outside the ministry on Wednesday.
Presidential elections are due to be held in three weeks.