Operation Harvest Festival (German: Aktion Erntefest) was the murder of up to 43,000 Jews at the Majdanek, Poniatowa and Trawniki concentration camps by the SS, the Order Police battalions, and the Ukrainian Sonderdienst on 3–4 November 1943. After the operation, about 10,000 Jews were left alive in various labor camps in the Lublin District. The bodies of the victims were burned by other Jews, who had been spared temporarily from death. With around 40,000 victims, Operation Harvest Festival was the largest single massacre of Jews by German forces during the Holocaust.