The Metropolitan Plan of Great Hsinking was influenced by the renovation plan of Paris in the 19th century, the garden city movement, and theories of American cities' planning and design in the 1920s. The city development plan included extensive tree planting. By 1934 Hsinking was known as the Forest Capital with Jingyuetan Park built, which is now China's largest Plantation and a AAAA-rated recreational area. In accordance with the Metropolitan Plan of Great Hsinking, the area of publicly shared land (including the Imperial Palace, government offices, roads, parks and athletic grounds) in Hsinking was , whilst the area of residential, commercial and industrial developments was planned to be . However, Hsinking's population exceeded the prediction of 500,000 by 1940. In 1941, the Capital Construction Bureau modified the original plan, which expanded the urban area to . The new plan also focused on the construction of satellite towns around the city with a planning of land per capita. Because the effects of war, the Metropolitan Plan of Great Hsinking remained unfinished. By 1944, the built up urban area of Hsinking reached , while the area used for greening reached . As Hsinking's city orientation was the administrative center and military commanding center, land for military use exceeded the originally planned figure of 9 percent, while only light manufacturing including packing industry, cigarette industry and paper-making had been developed during this period. Japanese force also controlled Hsinking's police system, instead of Manchukuo government. Major officers of Hsinking police were all ethnic Japanese. The population of Hsinking also experienced rapid growth after being established as the capital of Manchukuo. According to the census in 1934 taken by the police agency, the city's municipal area had 141,712 inhabitants. By 1944 the city's population had risen to 863,607, with 153,614 Japanese settlers. This population amount made Hsinking the third largest metropolitan city in Manchukuo after Mukden and Harbin, as the metropolitan mainly focused on military and political function. Japanese chemical warfare agents In 1936, the Imperial Japanese Army established Unit 100 to develop plague biological weapons, although the declared purpose of Unit 100 was to conduct research about diseases originating from animals. During the Second Sino-Japanese War (1937–1945) and World War II the headquarters of Unit 100 ("Wakamatsu Unit") was located in downtown Hsinking, under command of veterinarian Yujiro Wakamatsu. This facility was involved in research of animal vaccines to protect Japanese resources, and, especially,