Violent clashes in Egypt have entered a third day, as thousands protest the lack of action by authorities during a deadly stampede at a football match earlier this week.

Police in the capital, Cairo, fired tear gas and birdshot at demonstrators, who were chanting, yelling and throwing stones near the heavily guarded building for the Interior Ministry building. Across the street, the Tax Ministry building was in flames. Ambulances and volunteers carried the wounded away from the fighting through streets littered with debris.

Reports say at least a half-dozen people have died in the violence since it started in Cairo in the wake of a brawl at a football venue in the city of Port Said that left 74 people dead. The protesters accuse security forces of doing too little to stop the fighting and are calling for the ruling military council to surrender power to a civilian government.

On Friday, the sound of gunfire, tear gas cannisters and rocks smashing against police shields filled the air in and around Cairo's historic Tahrir Square following evening prayers. A doctor treating protesters near the square told the Associated Press that his field hospital has been overwhelmed by the injured.

Thousands of Egyptians also took to the streets in Alexandria.

The Health Ministry says almost 400 people have been injured in clashes with police in recent days, most overcome by tear gas.

Police have arrested 47 suspects for the football match mayhem. The military council's Field Marshal Mohamed Tantawi declared three days of national mourning and vowed to find those responsible.

Egypt's military-appointed prime minister also said the government has fired the board of Egypt's football federation and suspended Port Said's governor and security chiefs.

Lawmakers in Egypt's newly empowered parliament blamed police inaction for the tragedy and voted to conduct an investigation.

Western media quote survivors of the riot as describing how police negligence had facilitated Wednesday night's bloody events. Fans reported that security officers stood by as supporters of the winning home team, Al-Masry, attacked those of the top Cairo club, Al-Ahly, stabbing them and throwing them off bleachers. Panicked fans rushed for the exits but were crushed against locked gates.

Sepp Blatter, the head of world football's governing body, FIFA, sent a letter to Egypt's football federation demanding a full explanation of the disaster and calling it a “black day for football.” Egypt's football league has been suspended indefinitely.