Some 250 people from Japan, China and South Korea began Sunday excavating the remains of Korean forced laborers who were brought to wartime Japan, in Sarufutsu, Hokkaido.

The citizens and students will continue their work at the site of a common grave until Thursday and will pray for those who died while building the Imperial Japanese Army's airport nearby.

During the day, they dug down some 25 cm and unearthed three sets of remains.

The remains of another laborer were found during preliminary research there last October, the organizers said.