Unit 731: New "Horror Bunker" From Japan's WW2 Human Experimentation Camp Discovered

It’s hard to get your head around the sickening cruelty of Unit 731.


Tom Hale


Tom Hale

Senior Journalist

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

Japanese soldiers celebrate the capture of the Chinese city of Nanking in December 1937

Japanese soldiers celebrate the capture of the Chinese city of Nanking in December 1937.

Image credit: Everett Collection/

Chinese archaeologists say they have discovered an underground bunker that was used by scientists of the Japanese Empire to carry out ghastly human experimentation during World War II.

The site was recently found by the Heilongjiang Provincial Institute of Cultural Relics and Archaeology near the small city of Anda in Heilongjiang province, northeast China, according to South China Morning Post. It reportedly consists of an underground U-shaped structure, approximately 33 meters (108 feet) long and 20.6 meters (67 feet) wide, as well as well a series of interconnected tunnels and chambers.


The researchers claim this structure was a lab and holding cells used by the notorious Unit 731, a covert research and development unit set up in Japanese-occupied China. It started as a public health unit in the 1930s, but eventually mutated into a biological and chemical warfare research body that used Chinese, Korean, Russian, and American people as their test subjects. 

It’s hard to get your head around the sickening cruelty that’s associated with the name Unit 731. 

Under the command of General Shirō Ishii, people had vital organs and limbs removed for the sole purpose of studying blood loss and trauma. Human targets were used as live test subjects for a range of weapons, including grenades, flamethrowers, shrapnel bombs, pathogen-laced bombs, and chemical weapons. 

In other needlessly grueling experiments, people were subjected to low-pressure chambers until their eyes popped, electrocuted, dehydrated with hot fans, spun in centrifuges until death, injected with animal blood, and exposed to X-rays in lethal amounts. 


Estimates vary, but it’s believed between 3,000 to 12,000 men, women, and children lost their lives at Unit 731. Hundreds of thousands more died as a result of their initiatives to drop biological weapons, such as plague-infected animals, into live populations. 

In a grueling twist of this god-awful page in history, there is evidence that the US helped to cover up many of the atrocities committed at Unit 731. 

After the Empire of Japan surrendered in August/September 1945, the US secretly granted immunity from war crimes prosecution to many Japanese officials linked to Unit 731. There was also a concerted effort to withdraw vital information from the International Military Tribunal for the Far East, the Japanese equivalent of the Nuremberg trials. 

Shockingly, data from the Japanese human experimentation was transferred to Fort Detrick in Maryland where it was used to inform the US biological weapons program during part of the Cold War. 


The scale and depth of the horrors that occurred at the hands of Unit 731 staff underline the importance of remembering this abominable period in history, as hard as that may be. The archeologists who made this recently discover said the newly uncovered bunker “highlights the ongoing legacy of Unit 731’s atrocities and their impact on global efforts to prevent biological warfare.”


  • tag
  • archeology,

  • history,

  • Japan,

  • war,

  • concentraiton camps,

  • ww2,

  • human experimentation,

  • war crimes