Also the whole Russian emigre community of Kharbin in China. They were however given a grace period from 1945 to 1949, and a considerable number managed to flee to the West via Shanghai and Hong Kong.
As someone still living in China, I can speak to this issue with great accuracy.
Nearly all of the Russians living in Harbin did either four things : some were enjoined to return to the Soviet Union (quite a few went voluntarily, whereupon they were exiled to Kazakstahn (the mildest fate to befall them, others were not as fortunate) in the period 1945-1955; many others who had sullied their hands with the Japanese during the Manchuckuo Puppet Regime, fled to Tokyo with the retreating Japanese armies immediately in 1945 to avoid being executed for war crimes (this was not a small contingent by any means); many others departed for America, South Africa and Australia in the period 1949-1960 (the last immigrant actually left Harbin in 1960) and several thousand with strong local ties remained in both Harbin and Shanghai (although they had to pass through dangerous times later).
Manchuria was occupied by the Soviet Red Army from 1945-1955 and was considered a protectorate of the Soviet Union during that period. Initially, the Russians in Harbin welcomed the Red Army with open arms...only to discover that Stalin had not sent Red Army regulars but criminals freshly let out of prison and put into army uniforms. Harbin suffered a rampage of crime, rape and pillage at their hands until the commanding Generalissimo himself had enough and then they were replaced by regular troops. From 1947-1955, Harbin was Sovieticized but relatively, albeit not as prosperous as before.
The quality of Russian emigres in Harbin was not of a Petersburg level, although they did build numerous beautiful churches, buildings, mansions, palaces, train stations, bridges. The city was actually a focal point of culture. But the Russian inhabitants were from the provinces of Russia, not the center and not the then capital nor Moscow. The resident lists have been preserved and in pouring over the names one can many, many, many ordinary Russian middle-class names and very few, if any, of the names of the "500 families" that lived in downtown Petersburg.
There were also numerous Ukrainians, Balts, etc., etc. To this date, the only established and working Orthodox Church in China is located in Harbin.
If you can read Russian, here is a site with a lovely history of the city and great pictures :www.rusharbin.com