Port Said residents horrified by the football violence that left 74 people dead in their city accused police of incompetence on Thursday, some alleging a plot to enflame nationwide unrest.

Troops were stationed around the sprawling northern hub to prevent more violence after Wednesday night's unrest, but the city was calm as people gathered outside hospitals treating the hundreds of wounded.

Witnesses spoke of fans being crushed by the panicked crowds, trampled, beaten, stabbed and trapped as the anti-riot police were not able, or did not want, to control the crowds.

"The lack of security was not normal," charged one resident Medhat Mokhtar Naim who had been at the match between home-side Al-Masry and their fierce rival and Cairo star team Al-Ahly and saw people trapped in the stands.

"The security forces did nothing," added a young man, who gave his name only as Mohammed. "They just let people enter freely, the searches were not done properly."

Others questioned why police dogs were not brought out or security reinforced, with tension already brewing at half-time.

"What happened was a plot!" interjected another man on the pavement.

Another said "they should have reinforced security. That was not done, and then the lights went off."

"That was done on purpose, and it was planned so that there would be chaos," added Abdelfattah Mohammed, among the many who allege a deliberate attempt to feed insecurity a year after the fall of long-time ruler Hosni Mubarak.

The dead were flown back to Cairo's Zeinhom morgue where shocked family members stood around corpses wrapped in plastic sheets.

Mothers and sisters of the deceased, dressed in black, screamed in mourning as some of the bodies were taken out ahead of their burial.

A favoured theory is that the violence was staged in the interests of Mubarak's interior minister Habib el-Adly, who is on trial alongside the former dictator for the killing of demonstrators in last year's uprising.

Adly, widely hated among Egyptians, wants it to be known that while he is in prison, ‘there will chaos,’ claimed Port Said resident Ahmad Hassan Mostafa.

Al-Ahly's most ardent supporters, the Ultras, were active in the revolt that overthrew Mubarak.

They played a prominent role in defending anti-regime protesters when, one day during the uprising, Mubarak supporters on horse and camelback plunged into the crowds in Cairo's Tahrir Square before being pulled from their mounts or fleeing.

The Muslim Brotherhood, the most important political force to emerge in post-Mubarak Egypt, have also directly blamed the violence on supporters of the toppled dictator wanting to enflame unrest and destabilise the fragile country.

"Why did the police just stay sitting until the end of the match?" asked Mostafa. "Justice must be done."

As details of what happened in the chaos emerge, a doctor at a city hospital, Amir al-Masry, said the majority of the dead had suffocated but he also saw serious head wounds and fractures.

As investigations begin into the country's deadliest football violence, the government sacked Port Said security chief Essam Samak and city governor Kamal al-Ganzuri resigned.