Egypt's Muslim Brotherhood has described calls to hold demonstrations in front of its Muqattam headquarters on Friday as a continuation of aggression, stressing on its right to defend itself.

Clashes erupted between Brotherhood members and their rivals when activists on Saturday drew offensive graffiti on the Islamist group's headquarters.

Activists and journalists accused brothers of attacking men and women during tension that dragged on for two days.

Brotherhood member, Mahmoud Hussein, insisted in a press conference in Cairo on Thursday that if the police fails to protect public and private property, the group will not surrender their right to do so.

According to a local newspaper, 35 public figures and 21 political movements had confirmed that they would join tomorrow's demonstration which they consider a message to both the local and international community that the Brotherhood guidance office is the true ruler of Egypt.