Egyptian officials say at least 20 people have been killed in clashes near the Defense Ministry in Cairo.
The clashes occurred on May 2 between unidentified attackers and protesters who have been at the Defense Ministry for days, calling for an end to military rule.
Many of the protesters are said to be supporters of an ultraconservative Islamist who was disqualified from the presidential election because his mother held dual Egyptian-U.S. citizenship.
Two presidential candidates have suspended their campaigns over the clashes.
The first round of Egypt's presidential election is scheduled for May 23-24.
It will be Egypt's first since veteran ruler Hosni Mubarak was toppled amid popular protests in February last year.
Meanwhile, state television reported that Egypt's military chief of staff said on May 2 that the army may transfer power to an elected president on May 24 -- one month earlier than scheduled -- if the winner is decided in the first round.
Based on reporting by AFP, AP, and Reuters