Five people were killed on Wednesday when attackers stormed an anti-military protest near the defence ministry headquarters in Cairo, medics and a security official said.
The dawn assault sparked fierce clashes between the unidentified attackers and the protesters, who have been there for days calling for an end to military rule, with both sides hurling petrol bombs and rocks, the official said.
A doctor at a field hospital set up in the area said five people had been killed and at least 50 injured.
Health ministry officials said they could not confirm the toll until the bodies had reached the hospitals but said "dozens have been injured, some critically."
Egyptian state television said the clashes were ongoing.
The protesters, supporters of Salafist politician Hazem Abu Ismail, have been camped out since Saturday after the electoral commission barred the popular hardline Islamist from contesting next month's the presidential election.© ANP/AFP