Ten climbers died on two mountains in the Taisetsu mountain range in central Hokkaido since July 16, many of them succumbing to hypothermia in bad weather, police said July 17.

All of them were found to have died of hypothermia as weather conditions around the range were unstable July 16, with strong winds and rain, the police and the local meteorological observatory said.

There are few mountain lodges in the area and the victims are believed to have exhausted themselves in the poor weather, prompting the police to investigate the possibility that climbing tour operators and guides were professionally negligent, resulting in the deaths.