Editing Unit 731 (section)

=== Other units ===
{{Main|Epidemic Prevention and Water Purification Department}}

In addition to the establishment of Unit&nbsp;731, the decree also called for the creation of an additional biological warfare development unit, called the Kwantung Army Military Horse Epidemic Prevention Workshop (later referred to as Manchuria [[Unit 100]]), and a chemical warfare development unit called the Kwantung Army Technical Testing Department (later referred to as Manchuria [[Unit 516]]). After the [[Second Sino-Japanese War|Japanese invasion of China]] in 1937, sister chemical and biological warfare units were founded in major Chinese cities and were referred to as Epidemic Prevention and Water Supply Units. Detachments included [[Unit 1855]] in [[Beijing]], [[Unit Ei 1644]] in [[Nanjing]], [[Unit 8604]] in [[Guangzhou]], and later [[Unit 9420]] in [[Singapore]]. All of these units comprised Ishii's network, which, at its height in 1939, oversaw over 10,000 personnel.<ref>{{cite web|url=http://apjjf.org/-Tsuneishi-Keiichi/2194/article.html|title=Unit 731 and the Japanese Imperial Army's Biological Warfare Program – The Asia-Pacific Journal: Japan Focus|website=apjjf.org|date=24 November 2005 |access-date=2017-10-27|archive-date=2018-01-04|archive-url=https://web.archive.org/web/20180104190943/http://apjjf.org/-Tsuneishi-Keiichi/2194/article.html|url-status=live}}</ref> Medical doctors and professors from Japan were attracted to join Unit&nbsp;731 both by the rare opportunity to conduct human experimentation and the Army's strong financial backing.<ref name="NHK">The Truth of Unit 731: Elite medical students and human experiments (2017). NHK Documentary</ref>