During the Second Sino-Japanese War, Zhongshan was occupied by the Imperial Japanese Army which implemented Unit 8604 or Nami Unit, a secret military medical unit, related to Unit 731, that researched biological warfare and other topics through human experimentation.
During the Second Sino-Japanese War, in July 1937, the Imperial Japanese Army seized several islands belonging to Zhongshan. The Japanese army implemented Unit 8604 or Nami Unit, a secret military medical unit, related to Unit 731, that researched biological warfare and other topics through human experimentation.