The first killings of Polish intelligentsia took place soon after the German invasion, lasting from autumn 1939 until spring 1940. It was called Operation Intelligenzaktion, a plan to eliminate Poland's intelligentsia and leadership in the western part of the country, realized by Einsatzgruppen and Volksdeutscher Selbstschutz. As the result of this operation 60,000 Polish nobles, teachers, entrepreneurs, social workers, priests, judges and political activists were killed in 10 regional actions.[6][7] The Intelligenzaktion was continued by the German AB-Aktion Operation in occupied territories of central Poland.