Four people were killed and roughly 70 injured in Saturday's clashes outside the Egyptian Defence Ministry in Cairo's Abassiya district, Mohamed Fatouh, head of the Tahrir Doctors Association, told Al-Ahram's Arabic-language news website.
The report contradicts official health ministry statements that no one had been killed in the clashes.
Fatouh said that most of the deaths had been due to the use of live ammunition, adding that he expected reports of additional casualties within coming hours.
Fatouh went on to say that additional doctors and medical equipment were needed to attend to the injured. A number of those wounded, he noted, had already been taken to the nearby Demerdash Hospital for emergency medical treatment.
The clashes began late Saturday evening when unknown assailants attacked a group of protesters – mostly supporters of disqualified Salafist presidential candidate Hazem Salah Abu-Ismail – who had been staging a sit-in outside the ministry building.
The sit-in, which began Friday, was held to protest the recent decision by Egypt's Supreme Presidential Elections Commission to disqualify Abu-Ismail from the presidential race following allegations that his late mother had carried US nationality.
Protesters from other revolutionary groups – including Youth for Justice and Freedom, the Coalition of Revolutionary Forces, the Free Front for Peaceful Change and the Second Egyptian Revolution of Rage – all declared their solidarity with the sit-in's primary demand, namely the abdication of Egypt's ruling Supreme Council of the Armed Forces.