More than 600 people have been injured in clashes between police and protesters that broke out in downtown Cairo following a deadly football-match riot in Port Said, Egyptian health authorities said on Friday, according to RIA Novosti.

Thousands of hardcore football fans, known as Ultras, as well as various political movements marched on Cairo’s Tahrir Squre on Thursday to protest against what they called police negligence during Wednesday`s football disaster that left more than 70 people dead and up to 300 injured.

Thursday clashes broke out when a group of several hundred protesters marched from the square to the nearby Interior Ministry headquarters, chanting slogans against police and the country’s military rulers.

Police used tear gas to disperse the protesters who attempted to storm the ministry building, hurled stones at security officers and set fire to several cars and trees, state television said.

More than 200 of those injured in the clashes have been hospitalized, the Egyptian Health Ministry said in a statement. Earlier TV reports said some 10 police officers were among the injured.

The protests took place as Egypt has announced a national three-day mourning period following the riot at the Port Said stadium, which broke out when thousands of fans rushed onto the field after their home team from Port Said, Al-Masry, defeated Al-Ahly, one of Egypt’s top clubs from Cairo, 3-1 on Wednesday night.

By the early hours of Friday, a crowd of several thousand protesters have gathered in front of the Interior Ministry building, a RIA Novosti correspondent reported from the scene. Additional police units have been deployed to the site, although no fresh clashes have been reported.