According to Egyptian state television, a soccer riot that broke out in Cairo today left at least 14 dead (Update: authorities are now saying that the official death toll is at 22). The clash was between supporters of Egyptian Premier League club Zamalek and security personnel at Air Defense Stadium. On their Facebook page, a group of Zamalek ultras known as the White Knights claim that 22 were killed, and even posted several pictures of those they claim were killed by the police (link leads to graphic images).
It's not yet clear what sparked the fight between fans and police, but the AP spoke to sources who said that everything started when Zamalek fans tried to force their way into the stadium without tickets. The White Knights told a slightly different story, though, claiming on their Facebook page that the violence started because stadium officials didn't create proper entrance for them. From the AP:
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.
The photo above is from the White Knights' Facebook page, and shows the aftermath of the violence. They also posted photos of police in riot gear clashing with fans: