A protester holds an Egypt flag as she walks in front of riot police in front of the presidential palace in Cairo December 4, 2012. Reuters/Amr Abdallah Dalsh
Media reports said on Satuday evening that shots was heard in front of the presidential palace in Cairo.
Several tents of protesters at the palace were torched, al-Jazeera channel reported.
Scores of protesters were injured after unknown assailants had attacked them, al-Masry al-Youm gate reported.
The assailants shot at the protesters and set the tents on fire using petrol bombs.