A Japanese war criminal from World War II confessed that he and fellow military surgeons conducted live-body operations on captives, the State Archives Administration said on Wednesday.

They also performed "demonstrations of operations" by killing two captives, the administration said.

The second in a series of 31 handwritten confessions from Japanese war criminals published online features that of Ken Yuasa, who was born in Tokyo prefecture in 1916. He joined the Japanese war effort in January 1942.

According to a written confession by Yuasa on Nov 20, 1954, he "carried out vivisection demonstrations" on captives.

He "forced a large dose of anesthetic into the live body of a captive to check symptoms" in late March 1942 in Lu'an Army Hospital in Shanxi province.

"I practiced a 'tracheotomy' on another captive," he confessed, adding that after the experiment, "I, together with another military surgeon, strangled him with a belt."

On April 14, 1942, in the First Army Engineering Team POW internment camp in Taiyuan, Shanxi, Yuasa allowed "about 30 military surgeons living in army hospitals and field hospitals in Shanxi to perform surgical demonstrations on the live bodies of four captives".

In late August 1942, in the hospital's dissection room, more than 10 surgeons "conducted live-body operations on and killed" two captives, according to the confession.

In late March 1943 at the same hospital, more than 10 surgeons performed "operation demonstrations by killing" two captives, he added.

In early April 1944, Yuasa used two captives as "material for operation practice" for more than 10 military surgeons.

In late September 1944, after two captives were sent to the hospital under escort, "I provided one of them as material for an operation demonstration to about 10 military surgeons in the dissection room. The other one was given to the hospital director, who beheaded the captive," he confessed.

In late January 1945, Yuasa "provided" a captive "as material for a live-body operation demonstration to the military surgeons in the dissection room and about 10 military surgeons from the 14th Independent Infantry Brigade".

In mid-March 1945, about 10 military surgeons used two captives in custody as "material for operation demonstrations in the dissection room", he said.

Thirty-one confessions from Japanese war criminals will be published online to expose crimes committed by Japan in China during World War II.