TV footage shows players rushing for the locker room, fans beating each other, and firebombs being thrown.
The footage also shows riot police standing by, doing nothing, apparently completely overwhelmed.
According to reports, the violence erupted when fans of the teams accused each other of not supporting last year’s Arab Spring Revolution which ended the 30 year rule of dictator Hosni Mubarak. According to reports 74 people were killed during the riot and hundreds were injured.
The head of Egypt’s temporary military government, Field Marshal Mohamed Hussein Tantawi vowed to track down those responsible, “We will get through this stage. Egypt will be stable. We have a roadmap to transfer power to elected civilians.”