Deadly clashes erupted between supporters and opponents of deposed president Mohamed Morsi in Ibn Sandr Square in the suburb of Zeitoun in western Cairo.
A security source told Ahram Online that three people were killed in the violence.
According to Al-Ahram Arabic news website another 23 were injured.
Security forces are to trying to separate the rival groups, reported Al-Ahram.
Clashes reportedly erupted after hundreds of Muslim Brotherhood loyalists gathered to protest in Zeitoun.
According to Al-Ahram, gunfire was heard during the clashes.
On Friday, Morsi supporters staged demonstrations in Cairo and across the country as part of their calls for continuous rallies in the lead up to Sunday, a national holiday celebrating the 1973 war against Israel.
Another protester was killed in clashes between supporters and opponents of the deposed president in Manial in central Cairo.