The Kaimingjie germ weapon attack was a Japanese biological warfare bacterial germ strike against Kaimingjie, an area of the port of Ningbo in the Chinese province of Zhejiang in October 1940, during the Second Sino-Japanese War. These attacks were a joint Unit 731 and Unit 1644 endeavour. Bubonic plague was the area of greatest interest to the doctors of the units mentioned above. Six different plague attacks were conducted in China during the war, between the start of aggression and the end of the war. Using airdropped wheat, corn, scraps of cotton cloth and sand infested with plague infected fleas, an outbreak was started that resulted in a hundred deaths, infections and mild to severe bodily mutilations. The area was evacuated and a wall was built around it to enforce a quarantine. The area was eventually burnt to the ground to eradicate the disease. A later attack in 1942 on the same area by the two units led to the development of their final delivery system: airdropped ceramic bombs. Some work was conducted during the war with the use of liquid forms of the pathogen agents but the results were unsatisfactory for the researchers. The attacks were formed on the research of units 731 and 1644. These units researched the effects of various chemicals and pathogens that had the potential to be used as biological weapons on soldiers and civilians. The aim of the development of these biological weapons was the use of the weapons to further expand the Japanese empire across Asia. These units were arms of the Japanese top-secret biological weapons program. The program was headed by general Shirō Ishii. General Ishii devised the plans for the Kaimingjie germ weapon attack and played a major role in the Japanese biological weapons program, specifically through securing the program's funding. Background The Kaimingjie germ weapon attack occurred during the Second Sino-Japanese war (1937–45). This was a military conflict between the Republic of China and the Empire of Japan. The war broke out as a resistance to the Japanese expansion and influence on Chinese territory. In 1931 Japan's Kwantung army occupied Manchuria in an event known as the Mukden incident. Manchuria consisted of China's three north-eastern provinces. Before 1937 China and Japan fought in localised engagements but refrained from fighting a major war. In Manchuria, Japan established the puppet state of Manchukuo, which became a colony of Japan. Japan then continued