A number of prominent Syrian human rights groups appealed to the United Nations on Monday to open an investigation into the 2013 Tadamon massacre. The groups urged Linda Thomas-Greenfield, US envoy to the UN, to look into the massacre, in which 41 civilians were killed by Syrian regime forces in the Tadamon neighbourhood of Damascus in April 2013. “We are writing to demand immediate action to address this massacre, which amounts to a war crime, and hold perpetrators accountable at the UN Security Council,” the letter, issued by the Syrian Network for Human Rights (SNHR), read. The SNHR also ap…