Supporters of deposed Islamist President Mohamed Morsi called on Egyptians on Wednesday to hold "Friday of Martyrs" protests against the military takeover that ousted him seven weeks ago.
A grouping calling itself The National Coalition to Support Legitimacy, which has been demanding Morsi's reinstatement, said in a statement: "We will remain steadfast on the road to defeating the military coup."
Almost 900 people, including more than 100 soldiers and police, have been killed since the authorities forcibly dispersed Muslim Brotherhood sit-ins in Cairo last Wednesday.
The United States and the European Union are both reviewing aid to Cairo in light of the bloodshed, but Saudi Arabia, a foe of the Brotherhood, has promised to make up any shortfall.
Last Friday, protests by Morsi supporters turned violent with over a hundred reported dead across the country as the Muslim Brotherhood staged a "Day of Rage."
The army deployed dozens of armored vehicles on major roads around the capital after Morsi's Brotherhood movement called the demonstrations, and the Interior Ministry said police would use live ammunition against anyone threatening public buildings.
Earlier on Wednesday, a court ruled that deposed Egyptian leader Hosni Mubarak will leave jail as early as Thursday jolting a divided nation already in turmoil.
Convening at the Cairo jail where Mubarak is held, the court upheld a petition from his lawyer demanding the release of the man who ruled Egypt for 30 years until he was overthrown during the uprisings that swept the Arab world in early 2011.