Police clashed with supporters of deposed president Mohamed Morsy on Friday as Muslim Brotherhood-Ied groups called for continued demonstrations against the interim authorities and the military.
At Haram street in Giza, police dispersed protests by Morsy backers outside Al-Sabah mosque.
The march had planned to move toward Khatem Al-Morsalin mosque in Omraniya, but tear gas bombs forced demonstrators to flee to other streets. Five people were reportedly injured.
Demonstrators allegedly chanted anti-police and anti-army slogans and passed out leaflets urging citizens to boycott the constitutional referendum slated for 14 and 15 Jan.
They also allegedly spray painted phrases on nearby buildings calling for the boycott of the upcoming referendum.
Some locals formed groups to protect their stores from potential sabotage, while others joined the forces in chasing the protesters.
In Nasr City, clashes erupted between police and demonstrators at Al-Nafees street.
Police fired tear gas and demonstrators threw rocks back.
At Helmeyet al-Zaitoun, demonstrators set a police vehicle on fire.
Clashes between police and protesters have become a weekly tradition every weekend, as many protesters head out to the streets after Friday prayers.
Last Friday, at least 16 protesters were killed in clashes with police and army forces in a number of Egyptian cities.
Edited translation from al-Masry Al-Youm
