Supporters and opponents of ousted president Mohamed Morsi – removed by the military earlier this week – plan rival demonstrations on Sunday, with the former demanding Morsi's reinstatement and the latter supporting Morsi's overthrow.
A coalition supporting Morsi's reinstatement has called for protests on Sunday to reject Wednesday's "military coup" against the elected president by Egyptian Defence Minister Abdel-Fattah El-Sisi.
The Muslim Brotherhood-led National Alliance in Support of Legitimacy, a group formed recently to support Morsi, has called for mass rallies to "Protect the revolution."
The Egyptian Armed Forces deposed Morsi after millions took to the streets on 30 June to demand early presidential elections. Morsi supporters say the army's move represents a violation of "democratic legitimacy."
In an earlier statement, the National Alliance in Support of Legitimacy declared that Morsi was still president and condemned the arrest of several high-profile Muslim Brotherhood members by security forces.
Many Egyptians welcomed the military intervention, with many celebrating when Morsi was replaced earlier this week by the head of Egypt's High Constitutional Court (HCC).
The military announced a "roadmap" in coordination with opposition parties, whereby presidential and parliamentary elections would be held and the constitution amended.
The roadmap fulfilled opposition demands as set down in a petition campaign to oust Morsi signed by millions – the impetus behind the 30 June protests. The 'Rebel' campaign had collected signatures nationwide to impeach Morsi and call for early presidential elections.
The campaign had recommended the appointment of the HCC head as interim president and the formation of a new technocratic government to oversee a transitional phase.
The Rebel campaign is also calling for Sunday protests, urging Egyptians to defend what they describe as "popular legitimacy" in an attempt to counter what their opponents insist is Morsi's democratic legitimacy.
Fears run high as clashes between supporters and opponents of the ousted president in several Egyptian cities on Friday led to at least 36 deaths.
Despite Brotherhood leader Mohamed Badie's statement at a massive pro-Morsi rally in Cairo where he stressed the need for peaceful protest, supporters in many of the clashes were seen using weapons, as were their anti-Morsi opponents.
Residents of Cairo's middle-class Manial district said Morsi supporters were "heavily armed" and attacked them leaving at least seven dead, AFP reported.
Thousands of Manial residents took part in the funeral procession of those killed Friday.
The Brotherhood also held a funeral for those killed when Morsi supporters demonstrated Friday outside the headquarters of Egypt's presidential guard, believing Morsi was being held inside. They blame the military for killing several protesters.