CAIRO  — At least 74 people were killed and hundreds injured after soccer fans rushed the field in the seaside city of Port Said Wednesday following an upset victory by the home team over Egypt’s top club, setting off clashes and a stampede as riot police largely failed to intervene.

It was a bloody reminder of the deteriorating security in the Arab world’s most populous country as instability continues nearly a year after former President Hosni Mubarak was swept out of power in a popular uprising.

The melee — which followed an Egyptian league match between Al-Masry, the home team in the Mediterranean city, and Al-Ahly, based in Cairo and one of Egypt’s most popular teams — was the worst case of soccer violence in Egypt and the deadliest worldwide since 1996. One player said it was “like a war.”

In Cairo, fans angered that another match between Al-Ismaili and Zamalek was halted because of the Port Said violence set fire to the bleachers at the main stadium in the Egyptian capital, authorities said. No injuries were reported, and employees said firefighters extinguished the blaze before it caused much damage.

The clashes and ensuing stampede did not appear to be directly linked to the political turmoil in Egypt, but the violence raised fresh concerns about the ability of the state police to manage crowds. Most of the hundreds of black-uniformed police with helmets and shields stood in lines and did nothing as soccer fans chased either, some wielding sharp objects and others hurling sticks and rocks.

Security officials said the ministry has issued directives for its personnel not to “engage” with civilians after recent clashes between police and protesters in November left more than 40 people dead.

The violence also underscored the role of soccer fans in Egypt’s recent protest movement. Organized fans, in groups known as ultras, have played an important role in the revolution and rallies against military rule. Their anti-police songs, peppered with curses, have quickly become viral and an expression of the hatred many Egyptians feel toward security forces that were accused of much of the abuse that was widespread under Mubarak’s regime.

Egypt is not immune to soccer violence. In April, the ineffectiveness of the police force also was on display when thousands of fans ran onto the field before the end of an African Champions League game between local club Zamalek and Tunisia’s Club Africain. The hundreds of police on duty at Cairo International Stadium could not stop the violence then, either.

Activists scheduled rallies Thursday outside the headquarters of the Interior Ministry in Cairo to protest the inability of the police to stop the bloodshed.

Many gathered outside Al-Ahly club in Cairo, chanting slogans against military rule, and hundreds filed into Cairo’s main train station to receive the injured arriving from Port Said. “We die like them, or we ensure their rights,” the crowd chanted, along with slogans denouncing the military rulers.

In Port Said, residents marched early Thursday, denouncing the violence and saying it was a conspiracy by the military and police to cause chaos.