The clashes near the Defence Ministry which started late last night and lasted into the early hours of today has left 91 injured but no deaths, a health ministry official said.
Of the injured, 77 were quickly treated from wounds and left the hospitals shortly after, the official added.
However, Mohamed Fatouh, the head of the Association of Tahrir Doctors, which has treated the injured near the site of the clashes, told Ahram Online that his group could confirm that four were killed and at least 70 injured.
Shortly before midnight yesterday, unknown assailants had attacked tens of protesters who had been staging a sit-in since late Friday night near the Ministry of Defence headquarters near Abbasiya Square.
The protesters who included many supporters of the recently barred presidential candidate Hazem Salah Abu-Ismail as well as other activists were voicing their opposition to the decision by the Supreme Presidential Electoral Commission to disqualify the Salafist preacher from the race for Egypt president which is set for May, and some demanded the military council hand power to a civilian administration, Ahram Online said.
According to eyewitnesses, the attackers used molotov cocktail bombs and cement bricks in their assault on protesters, and gunfire was also heard.