A soccer fan is seen near a police car, which was set on fire by fireworks, during clashes between soccer fans and security forces in front of a stadium on the outskirts of Cairo, Feb 8, 2015. [Photo/Agencies]

Authorities say the violence began when hundreds of hard-core Zamalek fans known as Ultras White Knights tried to force their way into the stadium to attend the soccer match without tickets.

On their Facebook page, the White Knights said 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.

One fan, who spoke to The Associated Press on condition of anonymity out of fear of being targeted by police, 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," the man said.

Sunday's match, pitting Zamalek of Cairo against ENPPI, kicked off more than an hour behind schedule. Zamalek is leading the league, with ENPPI three points behind in second place. The teams drew 1-1.