Two unknown groups of people in civilian clothes clashed in Cairo's Tahrir Square and Abdel Moniem Riyad Square Tuesday night, after clashes reportedly broke out following an altercation between street vendors and protestors. Fifty-nine were injured within a half hour, according to the Ministry of Health, Egyptian ONtv reported. The two sides pelted each other with bottles and Molotov cocktails. The injured were transferred to field hospitals.