At least 73 people have been killed in fan clashes following a football match in the Egyptian city of Port Said, state television reports.
The deaths occurred after supporters invaded the pitch following a match between top-tier clubs Masry and al-Ahly on Wednesday.
It is feared the death toll could rise as scores have been injured.
It is the biggest disaster in the country's football history, said the Egyptian deputy health minister.
Some of the dead were security officers, the Associated Press quoted a morgue official as saying.
The BBC's Jon Leyne in Cairo says it appears fans had taken knives into the stadium.
Our correspondent says the lack of the usual level of security in the stadium might have contributed to the clashes.