The Soviets further demanded parts of eastern Finland, but the Finnish government refused. The Soviets invaded Finland in November 1939, yet despite numerical inferiority, the Finns kept the Red Army at bay. International opinion backed Finland, with the Soviets being expelled from the League of Nations. Embarrassed by their inability to defeat the Finns, the Soviets signed an interim peace treaty, in which they received territorial concessions from Finland. In June 1940, the Red Army occupied the Baltic states, which were forcibly merged into the Soviet Union in August; they also invaded and annexed Bessarabia and northern Bukovina, parts of Romania. The Soviets sought to forestall dissent in these new East European territories with mass repressions. One of the most noted instances was the Katyn massacre of April and May 1940, in which around 22,000 members of the Polish armed forces, police, and intelligentsia were executed.