Nineteen Zamalek fans were killed and 20 injured on Sunday evening as police attempted to disperse large crowds of fans who were making their way into a Cairo stadium to attend a football game in the Egyptian Premier league, health ministry spokesperson Hossam Abdel Ghaffar told Ahram Online.
This is the deadliest football-related incident since the infamous Port Said disaster three years ago.
The clashes reportedly started as police used tear gas to disperse members of the Ultras White Knights fan group in front of Cairo's Air Defence Stadium, a few hours before Zamalek played ENPPI in a top-of-the-table clash.
Earlier on Sunday night, medical sources had told the Ahram Arabic news website that the death toll exceeded 30.
However, prosecutors have put the number of those killed at 22.
The Ultras White Knights continue to say that 28 were killed in the clashes.
"They died of suffocation and stampede after being tear-gassed," a medical source at the Ahli Bank Hospital, which received 14 bodies, told Ahram Online.
Egypt's cabinet has suspended the league competition for an indefinite period following the latest tragedy, saying in a statement that Zamalek's fans failed to adhere to the safety procedures required to enter the stadium.
An eye witness told Ahram Online that families of the deceased screamed hysterically in the Ahli Bank Hospital.
Fan group Ultras White Knights shared photos of bodies of the victims on its official Facebook page, some of whom wearing the team's jersey, as well as a full list of their names.
The Egyptian interior ministry said the clashes occurred after Ultras White Knights members tried to attend the game without buying tickets.
A league crowd ban that has been in place since the 2012 Port Said tragedy, which left over 70 Ahly fans dead, was partially lifted last week as authorities said they would gradually allow fans to return to the stands.
"The Zamalek fans tried to get in by force, and we had to prevent them from damaging public property," the ministry said in a statement.
Ultras White Knights disputed the ministry's account, saying they were tear-gassed as many fans scrambled to get in, with a "tiny metal fence surrounded by barbed wire being the only gate opened for us."
Only 10,000 supporters were allowed to attend the match against ENPPI, with 5,000 tickets up for public sale and as many distributed by the club itself.
Zamalek board member Ahmed Mansour, son of outspoken chairman Mortada Mansour, said on his Facebook page: "You do not understand anything. You are not allowed to get in by force. No one will be allowed to attend the match without tickets,"
"Football is only for respectable fans. No thugs are allowed here," he added.
Egypt's prosecution said the bodies of the victims were transferred to a Cairo morgue. State news agency MENA said at least 25 were injured.
Match goes ahead
The match went ahead despite the deadly clashes but Zamalek's full-back Omar Gaber, a favourite figure among the ultras, withdrew in support of the fans.
The latest incident is a bitter reminder of the absence of safety measures in Egyptian football. The Port Said tragedy, which happened when Ahly's supporters were attacked by the home Masry fans following the end of a league game, sent shockwaves across the country and prompted authorities to impose a lengthy crowd ban.
The Egyptian Football Association (EFA) has repeatedly said new measures and procedures would be put in place to ensure fan safety but that did not materialise amid continued confrontations between hardcore fan groups, mainly those supporting Cairo teams Ahly and Zamalek, and security forces.
"Our blood is cheap ... Is this the regime you are trying to protect?" Ultras Ahlawy, whose members were killed in Port Said, said in a statement.
In January 2013, a court sentenced 21 Masry fans to death. Ahly fans generally welcomed the sentences but were angered that no police officers were convicted. More than 40 people were killed in protests after the verdict in Port Said.
In March 2013, an appeal court upheld the 21 death sentences, sentenced five people to life in jail and ordered jail sentences on the others, including 15 years for two police officers. Another 28 people were acquitted, including seven policemen.
However, almost one year later, a court ordered a retrial. The new trial is still ongoing.
League in limbo
There are doubts over whether the league competition will resume this season after it was postponed for an indefinite period.
Two of the last three editions were called off. The 2011-12 season was cancelled following the Port Said disaster and the following edition was also not completed following the ouster of Islamist President Mohamed Morsi in July 2013.
"Some of crowd, who did not have tickets, attempted to break into the stadium after the gate was closed. They also refused to be searched by the security forces before attacking them and damaging public and private property," Egypt's government said in a statement.
"The cabinet regrets the incident and expresses its condolences to the families of the victims."