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.

``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 1000 people were injured in the violence, but the interior ministry put the number at 248.

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 Mr Mubarak.

``There are dead people lying on the ground! There are dead people in the changing room,'' Al-Ahly striker Emad Meteab said.

``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.

Egypt's hated police force had recently come under fire for its heavy-handed tactics and had been given instructions to deal carefully with protesters, sources said.

The interior ministry said 47 people were arrested.

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,'' he said.