Unit Ei 1644 — also known as Unit 1644, Detachment Ei 1644, Detachment Ei, Detachment Tama,: 310–311 The Nanking Detachment, or simply Unit Ei, was a Japanese laboratory and biological warfare facility under control of the Epidemic Prevention and Water Purification Department. It was established in 1939 in Japanese-occupied Nanjing as a satellite unit of Unit 731. It had 12 branches and employed about 1,500 men.: 307
During the Second Sino-Japanese War, Unit Ei engaged in "producing on a mass scale lethal bacteria to be used as weapons against the Chinese forces and civilian population" and "took a direct part in employing bacteriological weapons against the Chinese forces and local inhabitants during the military operations of the Japanese troops," according to its Chief, Shunji Sato.: 73