Violent clashes reignited in Cairo on Friday between Egyptian police and protesters angered by reports of inadequate security at a soccer match that devolved into a riot this week, leaving 79 people dead.

Thousands of protesters gathered outside the Interior Ministry, prompting riot police to deploy tear gas for fear the men - some of them masked - would storm the building.

"The people demand the downfall of the field marshal," chanted the protesters, who waved flags from the popular soccer team Al-Ahly, which was playing in the game Wednesday when the riot broke out.

Gen. Marwan Mustapha, a spokesman for the Interior Ministry, said protesters who had taken over a government taxation building were throwing Molotov cocktails from the roof. More than 100 security forces were injured, including several by birdshot pellets, Mustapha said.

Similar clashes on Thursday left two dead in Suez and a military officer dead in Cairo, said Adel al Adawi, a Health Ministry spokesman.