After the occupation of Lithuania by the Soviet Union in June 1940, he created the so-called "Bulvičius group", which in 1941 evolved into the Vilnius branch of the Lithuanian Activist Front (LAF). The group planned an anti-Soviet uprising (see June Uprising in Lithuania) at the outbreak of the German–Soviet War. Vilnius LAF was to lead the uprising and Bulvičius was reserved the seat of Minister of Defense in the Provisional Government of Lithuania. The group established radio contact with Germany, but this radio signal was detected by the Soviet NKVD and Bulvičius was arrested on 9 June 1941. Fifteen other people were arrested leading to the near liquidation of Vilnius LAF command. At the outbreak of the war on 22 June, the prisoners were transported to Gorky (now Nizhny Novgorod) and tried by the Military Tribunal of the Moscow Military District. Bulvičius and seven others were sentenced to death and executed on 17 December 1941.
