In April 1944, the Home Army in the Vilnius Region attempted to open negotiations with Povilas Plechavičius, commander of the Lithuanian Territorial Defense Force, and proposed a non-aggression pact and cooperation against Nazi Germany. The Lithuanian side refused and demanded that the Poles either leave the Vilnius region (disputed between Poles and Lithuanians) or subordinate themselves to the Lithuanians' struggle against the Soviets. In the May 1944 Battle of Murowana Oszmianka, the Home Army dealt a substantial blow to the Nazi-sponsored Lithuanian Territorial Defense Force, which resulted in a low-level civil war between anti-Nazi Poles and pro-Nazi Lithuanians that was encouraged by the German authorities; it culminated with the June 1944 massacres of Polish and Lithuanian civilians in the villages of Glitiškės (Glinciszki) and Dubingiai (Dubinki) respectively.