Excavations are beginning at the site of a former medical school in Japan which could yield evidence of war-time experiments on prisoners.

The site in western Tokyo is said to be linked to Unit 731 of the Japanese Imperial Army, which used prisoners for biological warfare experiments.

The excavation was ordered after a former nurse came forward.

Toyo Ishii said workers were made to bury dozens of bodies there after the surrender at the end of World War II....