Supporters of ousted Egyptian President Mohammed Morsi called for mass demonstrations on Friday to show opposition to "the heinous coup against popular will."
A statement on the Muslim Brotherhood's website said that peaceful protest was "a right guaranteed to all Egyptians," saying it would hold the government responsible for its supporters' security.
The protests were given various names, including the "Friday of Rage" and the "Friday of Rejection."
Dozens of people have been killed in clashes between rival factions, police and soldiers since last weekend, with millions of people taking part in anti-Morsi protests.
Morsi was ousted as president by the military on Wednesday and replaced by top judge Adly Mansour on Thursday. Fresh elections have been promised.
The statement on the Brotherhood's website appealed to "the masses of the Egyptian people to mobilize in peaceful mass marches in all liberty squares and streets of Egypt, to be started from all mosques, after Friday prayers, to reject the heinous coup against popular will."
It was attributed to the "National Alliance in Support of Electoral Legitimacy."
"NASEL said that it feels rising public anger and the imminent danger threatening the nation as a result of the unprecedented military coup d'état against legitimacy derived from the will of the people," it said.
Morsi is under house arrest and the statement said NASEL would hold the "coup masterminds" responsible for his safety and "for preventing the elected president from contact with the people."