TOKYO (AP) — Depending on who you ask, the bones that have lain in a Tokyo warehouse for decades could be the remains of early 20th-century anatomy lessons or the unburied and unidentified victims of one of the country's most notorious war crimes.
A group of activists, historians and other experts who want the government to investigate the links to human biological warfare experiments during the war gathered last weekend to mark the 35th anniversary of their discovery and to renew calls for an independent panel to examine the evidence.
The Japanese government has long avoided discussing war crimes, including the sexual abuse of Asian women known as “comfort women” and Korean forced laborers in Japanese mines and factories, often citing a lack of evidence. Japan has apologized for its aggression in Asia, but since the 2010s it has been repeatedly criticized in South Korea and China for backtracking.
About a dozen skulls, many with cut wounds, and parts of other skeletons were unearthed on July 22, 1989, during construction of a Ministry of Health research institute on the site of the wartime Army Medical School. The school's close ties to a germ and biological warfare unit led many to suspect that they could be the remnants of a dark history that the Japanese government has never officially acknowledged.
Unit 731 and several related units, headquartered in then Japanese-controlled northeastern China, injected POWs with typhus, cholera and other diseases, according to historians and former members of the unit. They also say the unit performed unnecessary amputations and organ removals on living people to practice surgery and froze prisoners to death in endurance tests. The Japanese government has acknowledged only that Unit 731 existed.
Top Unit 731 officials were not tried in postwar tribunals because the U.S. sought to obtain chemical warfare data, historians say, although lower-ranking officials were tried in Soviet tribunals. Some of the unit's leaders became medical professors and pharmaceutical directors after the war.
Earlier research by the Ministry of Health found that the bones could not be linked to the unit. The ministry concluded that the remains most likely came from bodies used in medical education or taken from war zones for analysis, according to a 2001 report based on interviews with 290 people involved with the school.
It was acknowledged that some interviewees made connections to Unit 731. One said he had seen a head in a barrel that had been shipped from Manchuria, northern China, where the unit was based. Two others noted that they had heard that there were specimens of the unit stored in a schoolhouse, but they had not actually seen them. Others denied the connection, saying the specimens could have been pre-war specimens.
A 1992 anthropological analysis determined that the bones came from at least 62 and possibly more than 100 different bodies, mostly adults from parts of Asia outside Japan. The holes and cuts found on some of the skulls were made postmortem, the report said, but no evidence was found linking the bones to Unit 731.
However, activists say the government could do more to reveal the truth, such as publishing full transcripts of the interviews and conducting DNA testing.
Kazuyuki Kawamura, a former member of the Shinjuku prefectural assembly who has devoted much of his career to solving the bone mystery, recently obtained 400 pages of research material from the 2001 report through public information requests. He said the report showed that the government “tactfully omitted important information from witness statements.”
The newly released material does not provide conclusive evidence, but it does contain vivid descriptions: the man who described seeing a head in a barrel also said he helped move the head and then ran away to vomit. Several witnesses also suggested that further forensic investigation might establish a link to Unit 731.
“Our goal is to identify the bones and return them to their families,” Kawamura said. The bones are virtually the only evidence of what happened, he said. “We just want to find the truth.”
Health Ministry official Atsushi Akiyama said that witness statements had already been analyzed and incorporated into the 2001 report, and the government's position has not changed. A key missing link is documentary evidence, such as a label on a sample container or official documents, he said.
Documents, especially those relating to the atrocities committed by Japan during the war, were carefully destroyed in the final days of the war. It would be difficult to find new evidence.
Akiyama added that the lack of information about the bones would complicate DNA analysis.
Hideo Shimizu, who was sent to Unit 731 as a lab technician in April 1945 at age 14 and attended the meeting online from his home in Nagano, said he remembers seeing heads and body parts in formalin jars stored in a specimen room in the unit's main building. One that struck him most was a dissected abdomen containing a fetus. He was told they were “maruta” — tree trunks — a term used for prisoners selected for experimentation.
Days before the Japanese surrender on August 15, 1945, Shimizu was ordered to collect bones from the bodies of prisoners who had been burned in a pit. He was then given a pistol and a packet of cyanide to commit suicide if he was caught on his way back to Japan.
He was ordered never to tell anyone about his experiences at Unit 731, never to contact his coworkers, and never to apply for a job in the government or health care industry.
Shimizu said he can't say whether a specimen he saw at the 731 could be among the Shinjuku bones by looking at their photos, but that what he saw in Harbin should never be repeated. When he sees his great-grandchildren, he said, they remind him of that fetus he saw and the lives that were lost.
“I want young people to understand the tragedy of war,” he said.