Security officials said 17 police officers were injured and 258 people, including some with explosives and weapons, have been arrested in violent protests that erupted Friday, Ahram Online reported Saturday.
Clashes continued into the night around Cairo. A bus was smashed and several cars damaged in Nasr City, and police fired teargas into a student march at Al-Azhar University.
Police fired tear gas Friday at a crowd of 300 Brotherhood supporters blocking a road near a court facility in the suburb of Maadi. Protesters threw stones in response.
In Alexandria, hundreds of Islamists threw stones and fired birdshot at civilian opponents.
Eleven Muslim Brotherhood supporters were arrested Saturday in Port Said for allegedly attacking soldiers protecting the offices of the governor. The suspects allegedly had firebombs and fireworks at the time of their arrests.
Demonstrators are protesting a recent government decision to designate the Muslim Brotherhood a terrorist organization, accusing it of sponsoring attacks against security forces. The Brotherhood has denied any involvement in the attacks.