Kaimingjie germ weapon attack

开明街鼠疫灾难

Date	27 October 1940
Location	Ningbo, China
Coordinates	29°52′27″N 121°32′55″E / 29.87409°N 121.54869°E / 29.87409; 121.54869
Type	Biological warfare
Reporter	Xu Guofang & Ding Licheng
Deaths	1554

The Kaimingjie germ weapon attack (simplified Chinese: 开明街鼠疫灾难; traditional Chinese: 開明街鼠疫災難; lit. 'Kaiming Street Plague Disaster') was a secret biological warfare launched by Japan in October 1940 against the Kaiming Street area of Ningbo, Zhejiang, China.^[1] A joint operation of the Imperial Japanese Army's Unit 731 and Unit 1644,^[1] this attack was operated by military planes taking off from Jianqiao Airport in Hangzhou,^[2]: 89which airdropped wheat, corn, cotton scraps, and sand infected with plague fleas to target locations.^[1] From September 1940, Ningbo, Quzhou, and other places were subjected to various forms of biological warfares until the end of October 1940, when the attacks triggered a plague epidemic in Ningbo.^[3]

After the outbreak of the plague, the city authorities in Ningbo built a 4.3-meter-high isolation wall around the epidemic area, segregating patients and suspected cases, and eventually burned down the Kaiming Street area to eradicate the disease.^[4] Until the 1960s, this burned area was still referred to as the "plague field".^[5] According to the doctoral thesis of Junichi Kaneko, a military doctor of Unit 731, on October 27, 1940, Unit 731 spread 2 kilograms of plague bacteria over Ningbo, Zhejiang, using aircraft, resulting in a total of 1554 deaths from the first- and second-round infections.^[6][7]