Four protesters arrested during demonstrations in central Cairo on Saturday night against former autocrat Hosni Mubarak's acquittal are still in detention, the interior ministry said on Sunday.

The Front to Defend Egyptian Protesters (FDEP), an independent group of lawyers, told Ahram Online that security forces arrested 72 who were protesting near Tahrir Square in downtown Cairo late on Saturday.

"The protestors were later released, except for four who will be questioned on Sunday by the prosecution," said lawyer Amr Imam of FDEP.

Several hundred protesters gathered at a road leading into Tahrir Square to denounce Saturday's court verdict that dropped charges against Mubarak for his role in killing protesters during the 2011 uprising.

Two people died and 15 were injured, according to the health ministry, as security forces dispersed the protestors.

However, the interior ministry said that only one citizen died amid Saturday's protests, while five policemen were injured.

The head of south Cairo's prosecution is currently investigating one of the two casualties, who was believed to have died in the protests. Initial forensic examinations found six bullet shots in the body, which was taken to hospital by unknown people who immediately left without registering their information, the hospital said.

During Saturday's demonstrations, protesters carried pictures of some of those who were killed during the January 2011 uprising which ended Mubarak's 30-year rule. Demonstrators also chanted against both the government and the Muslim Brotherhood, from which ousted president Mohamed Morsi hails.

Police responded with tear gas and bird shot.