Hundreds of protesters on Friday headed to the High Court of Justice in downtown Cairo to protest the prosecutor general's action against several activists.
Prosecutor General Judge Talaat Abdalla ordered the summoning of several activists to question them in acts of violence at Mokattam district in Cairo last week.
Participants in the protest denounced President Mohamed Mursi's latest speech in which he threatened the opposition.
They demanded sacking Judge Abdalla and toppling the regime.
The oppositionist National Salvation Front and several political powers had called for today's protest under the title of "We are not threatened" to support several activists including Alaa Abdel Fattah, Nawara Negm, Hazem Abdel Azim and Ahmed Doma.
The prosecutor general had ordered summoning the activists following clashes near the Muslim Brotherhood's headquarters in Mokattam last Friday.
Security forces at the High Court of Justice sealed the doors as the number of protesters increased, Shorouk Portal said.