The board of directors of a community-funded religious centre in Cairo's Moqattam district – located near the Muslim Brotherhood's headquarters – issued a statement on Monday confirming that "members of the Islamist current" had taken control of the mosque during Friday's bloody clashes between protesters and Muslim Brotherhood supporters.
Anti-Brotherhood protesters had accused Brotherhood members and supporters of holding and torturing their opponents inside the mosque during street battles.
The Belal Ibn Rabbah Mosque lies in the Nafoura square where scuffles broke out between both groups on Friday.
Media reports in the past 72 hours had cited witnesses, some of whom said they are Moqattam residents, who claimed to have been brutally tortured at the hands of Brotherhood members inside the mosque on the day of the clashes.
The statement issued by the mosque's board of directors is the first document to corroborate claims made by anti-Brotherhood protesters that supporters of the ruling Islamist group had occupied the mosque.
Muslim Brotherhood Secretary-General Mahmoud Hussein had accused protesters of breaking into mosques following Friday's clashes.
The centre stated that it had filed an official legal complaint about the incident.
Egypt's prosecution-general, meanwhile, has subpoenaed on Monday several political activists accused of "inciting and committing violence against the Brotherhood's headquarters and group members."
Prosecutor-General Talaat Abdullah ordered the subpoenas based on a complaint filed by Brotherhood lawyer Abdel-Moneim Abdel-Maksoud on Monday morning against 169 individuals – including opposition figures and "thugs" – accused of of instigating attacks on the Islamist group's headquarters.