On Tuesday, Egyptian prosecution formally charged detained Muslim Brotherhood leader Mohey Hamed with inciting murder and arming supporters of deposed President Mohamed Morsi during the deadly clashes that broke out near Cairo University on 30 June.
Hamed was arrested on Saturday after he was found in an apartment in the east Cairo district of Nasr City. He is a member of the Brotherhood Guidance Bureau, the highest authority in the 85 year-old group's hierarchy.
On Monday, Egyptian prosecutors implicated the Islamist group's second-in-command, Khairat El-Shater, and Islamist preacher Safwat Hegazi in the same investigation.
At least 16 died during the clashes near Cairo University, close to Al-Nahda Square, where a pro-Morsi sit-in was being staged.
Egypt's security forces have been cracking down on the Islamist group and its allies in recent weeks, carrying out mass arrests of the group’s senior leaders and members nationwide.
Egypt's interim government accuses Brotherhood leaders of committing "acts of terror" against their opponents.