One person died and dozens were wounded during clashes between Muslims and Christians late Friday night outside a Coptic church in Egypt's city of Alexandria, state newspaper Al Ahram reported.
A quarrel between two young men, one Christian and one Muslim, morphed into a family feud that sparked clashes in a western district of Alexandria.
The two sides threw firebombs at each other before security forces intervened and cordoned off the area around the church, according to Reuters news agency.
Police arrested eight people after about two hours of fighting.
Christians make up about 10 per cent of Egypt's 84 million people and have complained that the authorities have failed to protect them since Mubarak was ousted, giving radical Islamists a free hand.
The news came hours after hundreds of opponents to President Mohammed Mursi rallied in the streets denouncing his rule and demanding early presidential elections.
Despite the low turnout, organizers of the “Tamarod,” or rebellion campaign, claim to have collected 2 million signatures on a petition to oust Mursi and hold early elections.
Demonstrators marched through various parts of Cairo before converging on Tahrir Square in a rally which was called for by a number of opposition groups.
The opposition accuses Mursi of governing only in the interests of his Muslim Brotherhood, while he insists he is the “president of all Egyptians.”
Since Mursi was elected last June, Egypt has continued to suffer from a serious political and economic crisis, and there have often been frequent clashes, sometimes deadly, between his opponents and supporters.