Internet users are circulating a video that appears to show members of Egypt's army assaulting an older female activist called Khadiga al-Hennawy.
Hennawy was near the cabinet building on Qasr al-Aini Street on Friday when clashes erupted between protesters and security forces.
In the video, two officers are seen dragging Hennawy by the hair. One lets go of her hair to kick her, before other officers join in, beating her with batons and dragging her out of view.
Another video released Saturday shows police mercilessly beating a man and a woman, whose clothes they tear off.