Clashes erupted between protesters and police in central Cairo on Thursday, leaving scores injured as authorities scrambled to contain mounting anger over post-football match violence that killed 74 people.
Black-clad riot police fired tear gas at demonstrators trying to reach the interior ministry. The protesters were furious at the lack of police intervention in Wednesday's violence in the northern city of Port Said.
The crowds accused the ruling military council, which took power when veteran president Hosni Mubarak was ousted one year ago, of mismanaging the country during a fragile transition.
"They know how to protect a ministry but not a stadium," one angry protester told AFP.
Thousands of people gathered in the roads leading to the interior ministry demanding the ouster of military ruler Field Marshal Hussein Tantawi, some calling for his execution.
Every tear gas canister fired sent the crowds running, only to regroup and march again.
State television said 628 people were injured in the clashes, mostly from tear gas inhalation.
"The security services are continuing to maintain the highest restraint following these aggressions," a security source told the Mena news agency.
Injured protesters were ferried away by motorbike as ambulances whizzed through nearby Tahrir Square, epicentre of last year's uprising that toppled Mubarak, towards the site of the clashes.
The demonstrators also clashed with police near the local security headquarters in the north-eastern city of Suez, leaving four injured, Mena said.
Wednesday's deadly violence between fans of Port Said home team Al-Masry and Cairo's Al-Ahly marked one of the deadliest incidents in football history and sent shares on the Cairo stock exchange plunging in Thursday trade.
Hundreds of Al-Ahly fans, wearing their team T-shirts and waving flags, were joined by others on the march from their club headquarters to the interior ministry via Tahrir Square.
"This was not a sports accident, this was a military massacre!" the crowds chanted.
UN Secretary General Ban Ki-moon urged the Egyptian government to take action.
"The secretary general trusts the government of Egypt will take appropriate measures to respond to this tragic incident, with the full cooperation of all concerned," said Ban's spokesman, without being more specific.
Prime Minister Kamal al-Ganzuri told an emergency session of parliament on the tragedy that the Egyptian football association's director and board had been sacked, as had Port Said's security chief.
Ganzuri added that the Port Said governor had also offered his resignation, and this had been accepted.
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However, furious MPs demanded the sacking of Interior Minister Mohammed Ibrahim who sat solemnly in the assembly, listening to accusations of negligence.
Wednesday's clashes erupted at the final whistle of a match which saw Al-Masri beat Al-Ahly 3-1.
Al-Masri fans invaded the pitch, throwing rocks, bottles and fireworks at Al-Ahly supporters, causing chaos and panic as players and fans fled in all directions, witnesses said.
They said Al-Ahly supporters had taunted their Al-Masry counterparts throughout the match, but others said this was no more than the usual match banter.
Al-Ahly's most ardent supporters, the Ultras, were active in the revolt that overthrew Mubarak.
State television ran footage of riot police standing rigidly in rows as pandemonium erupted around them.
The interior minister has said most of the deaths were caused by the crush, but medics said some people were stabbed.
The health ministry said 74 people were killed, including a policeman. Hundreds were reported wounded, and police said 47 people were arrested.
The ruling military announced three days of national mourning.
The post-match clashes -- blamed by the Muslim Brotherhood on Mubarak supporters -- came as Egypt struggles with a wave of incidents related to poor security.
Politicians, fans and players took to social media to express their fury over the clashes, which cap a year of political upheaval and unrest.
"There are dead people lying on the ground! There are dead people in the changing room," Al-Ahly striker Emad Meteab told the team's satellite channel.
"I won't play football any more until these people get justice," a furious Meteab said.
Egypt's hated police, who recently came under fire for heavy-handed tactics, had been given instructions to deal carefully with protesters, sources said.
World football governing body FIFA on Thursday called for a full report on the violence while its president, Sepp Blatter, expressed his shock at a "black day for football."
The Confederation of African Football (CAF) said a minute's silence will be observed at the Africa Cup of Nations this weekend in memory of the victims.
"African football is in a state of mourning," said CAF president Issa Hayatou.
The Muslim Brotherhood, Egypt's largest political force, accused Mubarak supporters of being behind the deadly violence.
Since Mubarak's ouster, Egypt has seen sporadic and sometimes deadly unrest coupled with a sharp rise in crime linked to the scarcity of police, who were heavily criticised for their crackdown on protesters during the uprising.