On 25 March 1949, 43,000 rural residents ("kulaks") and Latvian nationalists were deported to Siberia in a sweeping Operation Priboi in all three Baltic states, which was carefully planned and approved in Moscow already on 29 January 1949. This operation had the desired effect of reducing the anti Soviet partisan activity. Between 136,000 and 190,000 Latvians, depending on the sources, were imprisoned or deported to Soviet concentration camps (the Gulag) in the post war years, from 1945 to 1952.