The Syrian Civil Defense group, known as the White Helmets, uncovered at least 21 corpses as well as incomplete human remains on Wednesday in the Sayyida Zeinab suburb of the capital Damascus.

The discovery was made at a site previously used by Lebanon’s Hezbollah and Iran-backed Iraqi militias, both allies of deposed President Bashar Assad during the country’s civil war. The site included a field kitchen, a drugstore and a morgue, according to Ammar al-Salmo, an official with the White Helmets, a volunteer organization that operated in areas that were controlled by the opposition.