Read this: Critics labelled Gaddafi "despotic, cruel, arrogant, vain and stupid", with western governments and press presenting him as the "vicious dictator of an oppressed people". During the Reagan administration, the United States regarded him as "Public Enemy No. 1" and Reagan famously dubbed him the "mad dog of the Middle East". According to critics, the Libyan people lived in a climate of fear under Gaddafi's administration, due to his government's pervasive surveillance of civilians. Gaddafi's Libya was typically described by western commentators as "a police state". Opponents were critical of Libya's human rights abuses; according to Human Rights Watch (HRW) and others, hundreds of arrested political opponents often failed to receive a fair trial, and were sometimes subjected to torture or extrajudicial execution, most notably in the Abu Salim prison, including an alleged massacre on 29 June 1996 in which HRW estimated that 1,270 prisoners were massacred. Dissidents abroad or "stray dogs" were also publicly threatened with death and sometimes killed by government hit squads. His government's treatment of non-Arab Libyans has also came in for criticism from human rights activists, with native Berbers, Italians, Jews, refugees, and foreign workers all facing persecution in Gaddafist Libya. According to journalist Annick Cojean and psychologist Seham Sergewa, Gaddafi and senior officials raped and imprisoned hundreds or thousands of young women and reportedly raped several of his female bodyguards. Gaddafi's government was frequently criticized for not being democratic, with Freedom House consistently giving Libya under Gaddafi the "Not Free" ranking for civil liberties and political rights.

At what prison did extrajudicial executions occur according to HRW?
What is the answer? (If it cannot be answered, return "unanswerable")
Abu Salim