When Soviet Union occupied Lithuania on 15 June 1940, the Lithuanian Ministry of Internal Affairs was liquidated and replaced by the Soviet NKVD. Many former employees of the Ministry were arrested and imprisoned as so-called enemies of the people. When Nazi Germany invaded Soviet Union on 22 June 1941, Lithuanians organized an anti-Soviet June Uprising in hopes that they could restore Lithuanian independence. Therefore, they started restoring pre-Soviet state institutions under the Provisional Government of Lithuania. On 24 June 1941, the Provisional Government recreated the pre-war Ministry of Internal Affairs with three departments – State Security, Police, and Prisons. The State Security Department headed by Vytautas Reivytis. The government asked all those who worked there prior to 15 June 1940 to report back for duty. Many of them were just released from Soviet prisons.