Authorities say six Japanese high school students have been found unconscious after they were caught in an avalanche at a ski resort Monday morning.

Japan's Kyodo news agency said the six were found with no vital signs and feared to be dead.

The Tochigi government said three other students were also injured, and two more students and an instructor are missing.

The avalanche occurred around 9.20 am in the town of Nasu in Tochigi prefecture.

Japanese media said they were part of a group of about 50 students who were on a mountain climbing exercise at the ski area north of Tokyo.