During World War II Poles became the subject of ethnic cleansing on an unprecedented scale, including: Nazi German genocide in General Government, Soviet executions and mass deportations to Siberia from Kresy, as well as massacres of Poles in Volhynia, a campaign of ethnic cleansing carried out in today's western Ukraine by Ukrainian nationalists. Among the 100,000 people murdered in the "Intelligenzaktion" operations in 1939–1940, approximately 61,000 were members of the Polish intelligentsia. Millions of citizens of Poland, both ethnic Poles and Jews, died in German concentration camps such as Auschwitz. Unknown numbers perished in Soviet "gulags" and political prisons.