A riot broke out outside of a major football game in Egypt, with a stampede and fighting between police and fans killing at least 25 people.
The riot, only three years after similar violence killed 74 people, began ahead of a match between Egyptian Premier League clubs Zamalek and ENPPI at Air Defence Stadium east of Cairo on Sunday night.
Such attacks in the past have sparked days of violent protests pitting the country's hard-core fans against police officers in a nation already on edge after years of revolt and turmoil.
Egypt's public prosecutor has ordered an investigation.
The cabinet convened an emergency meeting to discuss the violence, Egypt's state television said.
What caused the violence wasn't immediately clear.
Security officials said Zamalek fans tried to force their way into the match without tickets, sparking clashes.
Fans have only recently been allowed back at matches and the Interior Ministry planned to let only 10,000 fans into the stadium, which has a capacity of about 30,000.
Zamalek fans, known as "White Knights," posted on their group's official Facebook page that the violence began because authorities only opened one narrow, barbed-wire door to let them in.
They said that sparked pushing and shoving that later saw police officers fire tear gas and birdshot.
A fan who tried to attend the game said the stampede was caused by police who fired tear gas at the tightly packed crowd.
"Those who fell down could not get back up again," he said, refusing to give his name.
The Zamalek fan group later posted pictures on Facebook it claimed were of dead fans, including the names of 22 people it said had been killed.
Egypt's hard-core football fans, known as Ultras, frequently clash with police inside and outside of stadiums.
They are deeply politicised and many participated in the country's 2011 uprising that forced out President Hosni Mubarak.
Many consider them as one of the most organised movements in Egypt after the Islamist Muslim Brotherhood, which the government later outlawed as a terrorist organisation following the 2013 military overthrow of Islamist President Mohammed Morsi.
The deadliest riot in Egypt soccer history came during a 2012 match when Port Said's Al-Masry team hosted Cairo's Al-Ahly.
That riot, at the time the deadliest worldwide since 1996, killed 74 people, mostly Al-Ahly fans.
Two police officers later received 15-year prison sentences for gross negligence and failure to stop the Port Said killings, a rare incident of security officials being held responsible for deaths in the country.
Seven other officers were acquitted, angering soccer fans who wanted more police officers to be held accountable for the incident and other episodes of violence.
In response, angry fans burned down the headquarters of Egypt's Football Association, also protesting its decision to resume matches before bringing those behind that 2012 riot to justice.
