Al Masry fans invaded the pitch after a surprise 3-1 win over Cairo club Al-Ahly in Port Said last night, with reports stating as many as 79 people died in the ensuing violence.

There have been claims security forces and police did not do enough to intervene, and the violence was tied up with the political power struggle in the country.

Al-Ahly's Portuguese coach Manuel Jose has returned to Portugal to ponder his future after being attacked, while his assistant coach Pedro Barny backed up the claims that security staff did too little.

FIFA, the game's world governing body, today asked the Egyptian authorities to explain exactly what happened.

FIFA said in a statement: "FIFA has asked the Egyptian authorities for a full report on the incidents in order to evaluate what happened."

In a letter to Egyptian FA president Samir Zaher, FIFA president Blatter offered support and said: "Today is a black day for football and we must take steps to ensure that such a catastrophe never happens again.

"Football is a force for good and we must not allow it to be abused by those who mean evil.

"I await further news from you concerning the circumstances of this tragedy."

Home fans reportedly armed with sticks and knives stormed the field after the final whistle.

Reports suggest some Al-Ahly fans suffocated, trapped in a narrow corridor as they fled the violence.

Al-Ahly coach Jose told www.el-ahly.com: "I was beaten with fists and kicks to the neck, head and feet. I saw our fans die before us and we are unable to do anything."

Assistant coach Barny added: "What happened was an unspeakable catastrophe.

"From the beginning of the game, the opposing team's fans were allowed to fire rockets and stones at us without any intervention.

"In the end, it turned into a state of madness without any role for the security in the stands.

"We tried to save the lives of some of the fans, but many died before our eyes."

There are also reports some Al-Ahly players have vowed not to play professional football again after witnessing the violence.

Egypt striker Mohamed Zidan expressed his shock and sadness at the tragedy.

Zidan, who plays his club football in Germany with Mainz, was born in Port Said and spent his youth career with Al Masry.

"The news and pictures from my home city Port Said shock me and affect me very much," the 30-year-old, who won the Bundesliga title with Borussia Dortmund last season, told the Mainz official website.

"Al-Masry are my home-town club, whom I played for for a long time, in this stadium as well.

"Since yesterday I have been on the phone a lot with my homeland. My family and my friends who live in Port Said, have not been directly affected by the disaster.

"My thoughts and my condolences are with the victims and their families."

The Egyptian Football Federation last night announced an indefinite suspension of all leagues in the country following the trouble.

Meanwhile, reports in Egypt have stated Al Masry president Kamel Abu Ali has resigned.

A minute's silence will be held before this weekend's quarter-final matches at the African Nations Cup in Gabon and Equatorial Guinea.

Confederation of African Football president Issa Hayatou, whose organisation are based in Cairo, told www.cafonline.com: "African football is in a state of mourning."