Doctors in four hospitals told AFP that the death toll had reached 73, as ambulances continued to ferry in the injured from the stadium.
Some of the deaths were the result of stab wounds, the doctors said.
A security official said the violence erupted as soon as the referee blew the final whistle in the match between Al-Ahly and Al-Masri clubs.
Fans of Al-Masri, which beat Al-Ahly 3-0, invaded the pitch and began to throw rocks, bottles and fireworks at the Al-Ahly fans.
Meanwhile in the capital, a fire broke out at Cairo Stadium during the first half of a match between Zamalek and Ismaili clubs, prompting officials to cancel the match.
Emergency services have managed to control the blaze, a security official said.