The Strong Egypt Party has called for sacking the government after scores of people were killed when Egyptian security forces opened fire on supporters of ousted President Mohamed Morsi near Cairo's Rabaa al-Adawiya Square in the early hours of Saturday morning.
"It seems the 'popular mandate' sought by security forces was to kill, not fight to terrorism," the party said in a statement, a copy of which was obtained by the Anadolu Agency.
At least 120 people were killed and 4,500 injured when security forces used live fire against Morsi supporters early Saturday morning near Rabaa al-Adawiya Square, the site of a month-long pro-Morsi sit-in, according to medics at a field hospital set up in the square.
The Strong Egypt Party, founded by former Brotherhood figure Abdel-Moneim Abul-Fotouh, called for "an immediate halt to the killings being committed by the interior ministry" - which controls Egypt's sprawling police apparatus "and its thugs."
The fatalities came shortly after tens of thousands of Egyptians took to the streets to support a call by army chief and Defense Minister Gen Abdel Fattah al-Sisi to give the army and the police "a popular mandate to confront violence".
Tens of thousands of Morsi supporters also staged mass rallies on Friday to demand the reinstatement of the ousted president.
Morsi, Egypt's first democratically elected president, was deposed by the army on July 3 after mass demonstrations against his regime.
Since then, tens of thousands of his supporters have been staging daily protests and sit-ins to denounce the military coup against the elected president.
Many of them have been camped out in Rabaa al-Adawiya Square in Cairo and Nahda Square in Giza.