Clashes between supporters of deposed president Mohamed Morsi, local residents and security forces Friday left at least five dead.
According to a medical source who spoke to Ahram Online on Satuday, the slain were killed in Cairo, Upper Egypt’s Minya, Aswan and Damietta in the Nile Delta.
Media advisor of the Ministry of Health, Ahmed Kamal, has later confirmed to Al-Ahram Arabic news website five were killed as a result of Friday's violence.
Kamel added that a total of 56 were injuured in Cairo, Giza, Minya, Ismailia, Fayoum and Suez.
Friday protests — known for being the largest of the week, and often followed by violent clashes — this week came only two days after the interim government declared the Muslim Brotherhood a terrorist group.
A total of 265 Muslim Brotherhood members were arrested, while three police vehicles were torched by pro-Morsi protesters across the country, announced the Ministry of Interior late Friday.
The demonstrations by Muslim Brotherhood supporters and loyalists in Alexandria, Sohag, Aswan, Fayoum, Beni Suef, Damietta, Beheira and Port Said and other areas came in response to protest calls by the Brotherhood-led National Alliance to Support Legitimacy.
On Thursday, an interior ministry spokesperson announced that anyone participating in a protest organised by the Islamist group would risk a five-year prison sentence.
Wednesday's decision to designate the Muslim Brotherhood a terrorist group came after the deadly bombing of Tuesday in the Delta city of Mansoura, killing 16 near Mansoura's Security Directorate.
The government blames the Muslim Brotherhood for orchestrating attacks on its buildings and security personnel since the ouster of Morsi 3 July.
The Muslim Brotherhood vehemently denied involvement in attacks on government buildings and security personnel.
Meanwhile, Ansar Beit Al-Maqdis, an Al-Qaeda-inspired Islamist militant group, claimed responsibility for the Mansoura blast.