FILE - A pink tape is marked on the ground on Feb. 21, 2011, at the site of a former medical school in Tokyo as Japan has started to excavate the site of the former school linked to Unit 731, a germ and biological warfare outfit during the war. (AP Photo/Koji Sasahara, File)
Members of a citizens group investigating the bones dug up from a wartime Imperial Army medical school site, hold the excavation anniversary on July 20, 2024, in Tokyo. Hideo Shimizu, seen on screen, who was sent to Unit 731 in April 1945 at age 14 as lab technician, joined the meeting online from his home in Nagano. (Kyodo News via AP)
FILE - A power shovel is used on Feb. 21, 2011 to dig the site of a former medical school in Tokyo linked to Unit 731, a germ and biological warfare outfit during the war. (AP Photo/Koji Sasahara, File)