Dozens raided the main headquarters of the ruling Muslim Brotherhood in Mokattam on Monday, following a night of clashes between the opponents and supporters of the Islamist group, an eyewitness said.
The raid came after a number of Brotherhood members escaped from inside the headquarters, reported the state-owned news agency.
During their escape, Brotherhood supporters opened fire on the attackers, which increased the number of victims to seven dead and 47 wounded, according to the Middle East News Agency.
The protesters have captured a member of Egypt's ruling Islamist group and handed him over to the police station.
On Sunday, some of the protesters threw stones and firebombs at the building until a fire erupted.