At least 1,000 people were reportedly injured in the violence on Wednesday when fans staged a pitch invasion in the Mediterranean city of Port Said, even though local team Al-Masry beat visitors from Cairo, Al-Ahly, Egypt's most successful club.
Angry politicians denounced the lack of security at the match and blamed military leaders for allowing, or even causing, the tragedy. The Muslim Brotherhood, the Islamist group that dominates parliament, saw an "invisible" hand at work.
"Down with military rule," thousands of Egyptians chanted at the main Cairo train station where they met injured fans returning from what a minister said was the scene of Egypt's worst football disaster.
Hundreds of protesters gathered outside the state television building and marches across the capital were planned.
Field Marshal Mohamed Hussein Tantawi, 76, who heads the ruling military council, took an unusual step of speaking by telephone to a television channel, the sport broadcaster owned by Al-Ahly, vowing to track down the culprits. The army announced three days of national mourning.
But it did little to assuage the anger of fans, who, like many Egyptians, are furious that Egypt is still plagued by lawlessness and frequent bouts of deadly violence almost a year since Mubarak was driven out and replaced by an army council.
As with past flare-ups, it quickly turned political.
Parliament will hold an emergency session on Thursday to discuss the violence.
"The people want the execution of the field marshal," fans chanted at the station where some injured disembarked. "We will secure their rights, or die like them," they said of the dead, as covered bodies were unloaded from the trains.
The post-match pitch invasion provoked panic among the crowd as rival fans fought. Most of the deaths were among people who were trampled in the crush of the panicking crowd or who fell or were thrown from terraces, witnesses and health workers said.
Television footage showed some security officers in the stadium showing no sign of trying to stop the pitch invasion.
One officer was filmed as people poured onto the field, talking on a mobile phone.
"The rush caused a stampede, people were pushing each other against the metal door and stepping on each other," said one witness who attended the match, 23-year-old Ossama El-Zayat.
"We saw riot police firing shots in the air, and then everyone got scared and kept pushing against the locked door. We didn't know whether police were firing live rounds or not. People were crying and dying," he said.
Several enraged politicians and ordinary Egyptians accused officials who are still in their jobs after the fall of Mubarak of complicity in the tragedy, or at least of allowing a security vacuum that has let violence flourish in the past 12 months.
"The security forces did this or allowed it to happen. The men of Mubarak are still ruling. The head of the regime has fallen but all his men are still in their positions," Albadry Farghali, a member of parliament for Port Said, screamed in a telephone call to live television.
Some saw the violence as orchestrated to target the "Ultras", Al-Ahly's dedicated fans whose experience confronting police at football matches was turned with devastating effect against Mubarak's heavy-handed security forces in the uprising.
They played a significant role in defending Cairo's Tahrir Square, the heart of the uprising against Mubarak, when men on camels and horses charged protesters last year. Thursday is the anniversary of the notorious February 2 camel charge.
The Brotherhood, whose Freedom and Justice Party won the biggest bloc in parliament, blamed an "invisible" hand for causing the violence and said the authorities were negligent.
"We fear that some officers are punishing the people for their revolution and for depriving them of their ability to act as tyrants and restricting their privileges," it added.
Others blamed "thugs", the hired hands or plain clothes police officers in Mubarak's era who would often emerge from police lines to crush dissent to his rule.
"Unknown groups came between the fans and they were the ones that started the chaos. I was at the match and I saw that the group that did this is not from Port Said," said Farouk Ibrahim.
"They were thugs, like the thugs the National Democratic Party used in elections," he said, referring to Mubarak's former party and the polls that were routinely rigged in its favour.
The two football teams, Al-Masry and Al-Ahly, have a history of fierce rivalry. Witnesses said fighting began after Ahly fans unfurled banners insulting Port Said and one descended to the pitch carrying an iron bar at the end of the match.
Al-Masry fans poured onto the pitch and attacked Al-Ahly players before turning to the terraces to attack rival supporters.
"I saw people holding machetes and knives. Some were hit with these weapons, other victims were flung from their seats, while the invasion happened," Usama El Tafahni, a journalist in Port Said who attended the match, told Reuters.
Many fans died in a subsequent stampede, while some were flung off their seats onto the pitch and were killed by the fall. At the height of the disturbances, rioting fans fired flares straight into the stands.
Television footage showed fans running onto the field and chasing Al-Ahly players. A small group of riot police formed a corridor to protect the players, but they appeared overwhelmed and fans were still able to kick and punch players as they fled.
Hospitals in the Suez Canal zone were put on alert and dozens of ambulances were sent to Port Said from the Canal cities of Ismailia and Suez, said an official in the zone's local ambulance service.
Tantawi said a fact-finding committee would be set up and pledged that the army's plan to hand over power to civilians would not be derailed. The army has promised to go back to barracks by the end of June after a presidential election.
"Egypt will be stable. We have a roadmap to transfer power to elected civilians. If anyone is plotting instability in Egypt they will not succeed," he told Al-Ahly's channel.
Interior Minister Mohamed Ibrahim said 47 people were arrested. Egypt's football federation said it was indefinitely delaying matches for the Egyptian premier league.
Al-Ahly said in a statement it was suspending all sports activities and was mourning for three days after the pitch invasion.