As the Second World War began, there were 30,000 Jews living in Kaunas, comprising about 25% of the city's population. When the Soviet Union took over Lithuania in 1940, some Jewish Dutch residents in Lithuania approached the Dutch consul Jan Zwartendijk to get a visa to the Dutch West Indies. Zwartendijk agreed to help them and Jews who had fled from German-occupied Poland also sought his assistance. In a few days, with the help of aides, Zwartendijk produced over 2,200 visas for Jews to Curaçao. Then refugees approached Chiune Sugihara, a Japanese consul, who gave them a transit visa through the USSR to Japan, against the disapproval of his government. This gave many refugees an opportunity to leave Lithuania for the Far East via the Trans-Siberian railway. The fleeing Jews were refugees from German-occupied Western Poland and Soviet-occupied Eastern Poland, as well as residents of Kaunas and other Lithuania territories. The Sugihara House, where he was previously issuing transit visas, currently is a museum and the Centre For Asian Studies of Vytautas Magnus University.