Unit 731 conducted brutal germ warfare experiments between 1935 and 1945.
Chinese archaeologists find a World War II "horror bunker" where Japanese researchers carried out horrifying human experiments and gathered data.
According to The Independent, the site is in northeast China, near the city of Anda in Heilongjiang province, and was purportedly used during the Second World War by Japanese scientists to conduct horrific experiments on human subjects.
The site is reported to have been used by the infamous Unit 731 of the Japanese Imperial Army, which conducted some of the most brutal germ warfare experiments between 1935 and 1945.
The South China Morning Post reported, "Historical records show Unit 731's experiments at the Anda site included infecting prisoners with deadly diseases and testing new biological weapons. Some of the most gruesome studies were conducted in underground bunkers designed to contain and control the spread of infectious agents."
"It also highlights the ongoing legacy of Unit 731's atrocities and their impact on global efforts to prevent biological warfare," said the researchers from the Heilongjiang Provincial Institute of Cultural Relics and Archaeology.
The Anda special test field, constructed in 1941, served as Unit 731's largest, best-equipped, and most-used testing facility.
The Bacteriological Warfare Department, which oversaw it, conducted the majority of its experiments on humans housed in specialised prisons.
In the year 2018, the identities of 3,607 people who worked for Japan's notorious World War Two-era Unit 731 research group have been released in response to a request by Katsuo Nishiyama, a professor at Shiga University of Medical Science.