The Abbassiya district of the capital where the defence ministry is located was calm on yesterday after the military detained 300 people following Friday's clashes which left two people dead including a soldier, and hundreds injured.
The curfew was in effect between 2100 GMT and 0400 GMT in the morning.
The protests had started in objection to the disqualification of Islamist presidential hopeful Hazem Salah Abu-Ismail.
His supporters took to the ministry after huge marches Friday before last to call for him returning to the race.
Abu-Ismail did not comment on the violence, injuries or the deaths but called on his supporters to take to the streets again in order to bring down the military rule.
The Supreme Council of the Armed Forces (SCAF), which took charge after Mubarak was ousted, has vowed to hand power to civilian rule when a president is elected.
But protesters believe the army wants to maintain a degree of power even after the election and fear the polls will be rigged in favour of a pro-military candidate.
The presidential election is scheduled for May 23 and 24 with a run-off for June 16 and 17 if there is no outright winner.
