The Sabra and Shatila massacre took place in the Sabra and Shatila Palestinian refugee camps in Beirut, Lebanon between September 16 and September 18, 1982, during the Lebanese civil war. Palestinian and Lebanese civilians were massacred in the camps by Christian Lebanese Phalangists while the camp was surrounded by the Israel Defense Force. In that period of time, Israel was at war with the PLO in Lebanon. Israeli forces occupied Beirut, dominated the refugee camps of Palestinians and controlled the entrance to the city. After the assassination of Bachir Gemayel, leader and president-elect of the Lebanese Kataeb Party, a Maronite group, also called Lebanese Forces militia group, entered the camp and murdered inhabitants during the night. The exact number of victims is disputed, from 700–800 to 3,500 (depending on the source). This info from wikipedia