Police Battalion 303's actions quickly escalated to genocide while in the occupied Soviet Union. During the summer months, the battalion took part in joint actions with the 1st SS Infantry Brigade of the Waffen-SS, both providing support and undertaking independent killings. The brigade's report of 19 August to the Command Staff Reichsführer-SS (SS operational staff set up for the invasion) noted that the battalion and the brigade jointly participated in "combat of gangs".[6]