At least 11 people were killed and 52 others injured on Friday in clashes across Egypt between supporters of ousted president Mohamed Morsi and security forces, the health ministry said, Xinhua reported.
"Four were killed in Cairo, two in Alexandria, two in Ismailia and two in Fayoum and one in Beni Sweif," official news agency MENA quoted the health ministry's media adviser Ahmed Kamel as saying.
Kamel noted that seven of the injured people have been discharged from hospitals and the other 45 are still under treatement.
Following the Friday prayers, hundreds of Morsi's supporters took to main squares nationwide to protest against the armed forces, the police and the new draft constitution.
The protesters at Faysal district in Giza hurled Molotov cocktails at an armored police vehicle and set it on fire. They also blocked the roads and fired at police officers, the official news agency MENA reported.
State TV footage showed hundreds of Morsi's loyalists protesting in eastern Cairo's Nasar City, carrying posters against the interim government and Defense Minister Abdel-Fattah al-Sisi who led the ouster of Morsi in July.
Egyptian security forces have intensified their presence in Cairo's main streets following calls for renewed demonstrations by the National Alliance to Support Legitimacy, a pro-Morsi coalition led by the Muslim Brotherhood.
The coalition urged "the people to continue their rage and peaceful resistance" in preparation for another demonstration on Jan. 8, the date set for the second session of Morsi's trial over charges related to inciting violence and murdering of protesters outside the presidential palace in early December 2012.
The Islamists' protests are defiant to the government's protest law and the recent decision to declare the Brotherhood as "a terrorist group," only one day after a deadly blast hit a security building in Daqahliya province.