Security forces engaged in a firefight with unknown armed men in Giza’s Mohandiseen near on Friday evening after the curfew began at 7pm.
A security source told Al-Ahram’s Arabic site the exchange started when the assailants opened fire on police forces, who retaliated immediately.
No injuries or deaths were reported.
The fight erupted a few hours after other clashes had taken place nearby in the same area of Mohandiseen, leaving at least three dead.
The clashes took place between protesters supporting deposed president Mohamed Morsi and police forces in the area.
At least six protesters have been confirmed dead in clashes with security forces on Friday in Giza, Zagazig and Port Said.
Nationwide protests to “reclaim legitimacy” were organised by the Muslim Brotherhood's National Coalition to Support Legitimacy.