At least 51 people were killed and 268 injured nationwide on Sunday in clashes between supporters of deposed president Mohamed Morsi and security forces or supporters of the military.
According to health ministry official Khaled El-Khatib, most of the casualties were killed in Cairo and Giza, while Beni Suef and in Delga in Minya saw deaths too.
The interior ministry announced that at least 200 pro-Morsi supporters were arrested in their attempt to "storm Egyptian public squares" on Sunday.
The National Alliance to Support Legitimacy, a coalition of Islamist forces supporting Morsi, claimed that at least 11 pro-Morsi protesters had been killed in clashes in Ramsis Street, a site of previous clashes in downtown, between security forces and pro-Morsi protesters.
According to the Muslim Brotherhood-led coalition the injured and the dead were transferred to Sadanawi hospital in downtown Cairo.
The Brotherhood’s Freedom and Justice Party, which Morsi headed before winning the 2012 presidential elections, stated that it holds responsible "the commanders of the 3 July coup" and particularly army chief General Abdel-Fattah El-Sisi and Interior Minister Mohamed Ibrahim for the "crimes of violence" committed against the protesters.
In a statement issued on Sunday, the party called on human rights organisations to condemn the "crimes."
Deadly clashes erupted in Cairo as pro-Morsi marches protesting against the military headed to Tahrir Square, where thousands were celebrating the 40th anniversary of the 1973 war against Israel and voicing support for the army.
Confrontations also took place outside the capital.
Sunday marks the 40th anniversary of the 1973 Arab-Israeli war and is a national holiday in Egypt.