effectively losing diplomatic rights, and became a part of the Imperial Japan in 1910. In the early 20th century, Korean immigration to Manchuria steadily increased, either by refugees fleeing from Japanese rule, or from encouragement by the Japanese government for people to develop the land. Some local Chinese governments welcomed the Korean immigrants, as they were a source of labor and agricultural skill. In the meantime, Japan began to expand into northeast China. One of the regions the Japanese targeted was Jiandao (known in Korean as Gando). The Japanese claimed that Jiandao included territory of four counties (Yanji, Wangqing, Helong and Hunchun) of Jilin Province. The Japanese further claimed ethnic Koreans living in this region should be placed under the jurisdiction of Imperial Japan. The Japanese first infiltrated Jiandao in April 1907 to collect information and data. On August 7, 1907, Japanese troops invaded Jiandao and claimed that the "Jiandao Issue" was "unsettled" (see reference: Jiandao Massacre). In the Jiandao Convention of 1909, Japan affirmed territorial rights of the Qing over Jiandao after the Chinese foreign ministry issued a thirteen-point refutation statement regarding its rightful ownership. Japan agreed to withdraw its invading troops back to Korea in two months. The treaty also contained provisions for the protection and rights of ethnic Koreans under Chinese rule. Nevertheless, there were large Korean settlements and the area remained under significant Japanese influence. Despite the agreement, Koreans in Jiandao continued to be a source of friction between the Chinese and Japanese governments. Japan maintained that all ethnic Koreans were Japanese nationals, subject to Japanese jurisdiction and law, and demanded rights to patrol and police the area. The Qing and subsequent local Chinese governments insisted on its territorial sovereignty over the region. After the Mukden Incident of 1931, the Japanese military (the Kwantung Army) invaded Manchuria. Between 1931 and 1945, Manchuria was under the control of Manchukuo, a Japanese puppet state. From 1934 the area formed a new Jiandao Province of Manchukuo after the old Jilin Province was split into Binjiang, Jiandao and a rump Jilin. This period initiated a new wave of Korean immigration, as the Japanese government actively encouraged (or forced) Korean settlement in order to colonize and develop the region. The Japanese also moved to suppress resistance in the region. Within three and half years (from September 1931 to March 1935), Japanese regular forces and police murdered 4520 people. During and after