Protesters and police engaged in sporadic clashes yesterday at security headquarters in Cairo as violence raged into a fourth day and the interior minister leapt to the defence of his reviled forces.

The fighting was sparked by the perceived failure of Egypt’s military rulers and police to prevent football-linked violence following a match in the northern city of Port Said on Wednesday that left 74 people dead.

Clashes have been fuelled by police action, including the use of tear gas and birdshot, against protesters, with the health ministry reporting at least 12 people killed in Cairo and Suez since Thursday.

Hundreds of riot police yesterday blocked roads leading to the interior ministry headquarters in the centre of the capital, facing down youths throwing rocks and petrol bombs.

Police erected several concrete block walls on the roads leading to the ministry, which has become the nerve centre of the skirmishes, while entrenching themselves behind coils of barbed wire.

“There is an insistence (by protesters) on storming the interior ministry and implementing a plot,” said Interior Minister Mohammed Ibrahim, whose predecessor was sacked in a Cabinet shuffle in November following similar clashes.

Mr Ibrahim said police did not want to harm any “revolutionaries” among the protesters, but were prepared to confront others “who want to ruin the country.”

Police earlier moved on protester positions in the rock-strewn streets, firing birdshot and detained medics at a field hospital but later released them, a doctor, Mustafa Nabil, said.

The protesters denied they intended to storm the ministry, several hundred metres from Tahrir Square, the epicentre of the uprising that overthrew president Hosni Mubarak a year ago but left the military in charge.

“My heart burned at what happened in Port Said, and we all know that the police are responsible,” said protester Ahmed Farah.