Bolshevik supporters conducted a partisan struggle in the city. From 1916 through 1922, Vladivostok's population went from 97,000 to 410,000 as opponents of the new regime (including the White Army) retreated to the east. From 1920 to 1922, cultural refugees from Moscow and Saint Petersburg founded two conservatories, two theaters and several symphony orchestras and published art magazines. After the Bolshevik victory, most moved abroad and by 1926 Vladivostok had a population of 108,000. On October 25, 1922, the last interventionist units left the city, and the Red Army assumed control. On November 15 the Far Eastern Republic, which had existed since 1920, became part of the RSFSR. The Bolsheviks understood Vladivostok's strategic importance, and during the 1920s and 1930s reconstruction of its port began. In the early 1930s direct air service to Moscow began, and in 1932 the city became the base of the Pacific Naval Fleet. During the early 1920s, Far Eastern State University was established in Vladivostok; in the late 1930s, under Stalin, it was closed for twenty years. In 1925 the Pacific Scientific-Commercial Station, reorganized as the Pacific Scientific-Research Institute of Fisheries and Oceanography (TINRO) in 1930, was established in the city. In 1932, the Far Eastern Division of the USSR Academy of Sciences was founded. In 1926, Vladivostok's first radio station began broadcasting. Three theaters and three cinemas were opened in the city in 1931. The Primorye Picture Gallery's collection was assembled from 1929 to 1931. About 1,000 pictures were brought there from the Hermitage, the Russian Museum and the Tretyakovskaya Gallery. Many ethnic groups considered rebellious by Stalin's eyes, including Chinese, Manchu, Jews, Ukrainians, Poles, Crimean Tatars, Chechens, and Armenians, were transported. During the 1930s mass repression began in the country, and a transit camp for political prisoners sent from western Russia to Kolyma was opened in Vladivostok. The prisoners arrived by train and left on prison ships in terrible conditions. Soviets at first, after 1939 the prisoners came from Eastern Europe and were Japanese POWs after World War II. Factories, ports and cities in the Far East were built by prison labor during the 1930s. After American pilots bombed Tokyo on April 18, 1942, one of the sixteen B-25 bombers landed in Vladivostok when it ran out of fuel; the bomber was confiscated and its crew interned. Although Captain Edward York and his crewmates were well-treated, diplomatic efforts to return them to the