CAIRO -- At least 74 people were killed and hundreds injured when rival fans clashed Wednesday  after a football match in Port Said, highlighting a security  vacuum  in  post-revolution  Egypt.

In  one of the deadliest incidents in  the sport’s  history, violence erupted  as soon as the referee blew the  final whistle in a match which saw home team Al-Masri  beat Cairo’s Al-Ahly 3-1.

Al-Masri  fans flooded the pitch, throwing rocks, bottles and fireworks  at Al-Ahly supporters, sparking chaos and panic as Al-Ahly players and fans ran  in all  directions trying to flee, witnesses said.

Photos of bleeding players circulated on the Internet.

Gunfire was also reported on the  main road leading to Port Said  from Cairo, and troops were deployed to prevent further clashes.

“The death toll has now reached 74, including one policeman, in the  unrest after the match between Al-Ahly and Al-Masri,” the  health  ministry said in a statement.

“Most of the people were killed in the crush,” Interior Minister Mohammed Ibrahim added, while  medics said some of the deaths  were the result of stab wounds.

State television said around 1,000 people were injured in the violence but the interior ministry put the number at 248.

The ruling military announced three days of national mourning, while the Port Said security chief was summoned to Cairo over the events.

The clashes in the  northern city --  blamed by the Muslim Brotherhood on supporters of fallen president  Hosni Mubarak --  came as  the country struggles with a wave of incidents linked to poor security.

Shops in Port Said, which sits at the entrance to the Suez Canal, shut their doors as private cars helped to shuttle the injured across the city to hospitals.

Politicians, fans and players took to social media to express their fury over the violence which caps a year of political upheaval and unrest after the uprising that unseated Mubarak.

“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 anymore until these people get justice,” a furious Meteab said.

State television showed footage of riot police standing rigidly in rows, as pandemonium erupted around them.

In  Geneva, FIFA  president Sepp Blatter said he was “very shocked and saddened to learn this evening that a large number of  football supporters  have died or been injured.”

“This is a black day for football. Such a  catastrophic situation is unimaginable and should not happen,” he said.

Prime Minister Kamal al-Ganzuri was to hold an emergency cabinet meeting on Thursday to discuss the events.