Approximately 13,000 men served in the Lithuanian Auxiliary Police Battalions. 10 of the 26 Lithuanian Auxiliary Police Battalions working with the Nazi Einsatzkommando, were involved in the mass killings. Rogue units organised by Algirdas Klimaitis and supervised by SS ''Brigadeführer'' Walter Stahlecker started the Kaunas pogrom in and around Kaunas on 25 June 1941. In 1941, the Lithuanian Security Police (''Lietuvos saugumo policija''), subordinate to Nazi Germany's Security Police and Nazi Germany's Criminal Police, was created. The ''Lietuvos saugumo policija'' targeted the communist underground.