Ten people from a tour boat missing off the coast of Japan's northernmost prefecture of Hokkaido have been confirmed dead.

The boat, called Kazu One, went missing on Saturday during a cruise off the Shiretoko Peninsula. It was carrying 26 passengers and crew members, including two children. The ship reported it was taking in water and about to sink before losing contact.

Japan Coast Guard and Self-Defense Forces personnel found 10 people in the water or on rocks around the tip of Cape Shiretoko on Sunday.

The Coast Guard says the 10 people were taken to hospitals and other locations but were later confirmed dead.

The victims comprise seven men and three women. Coast Guard officials are trying to identify them. Search operations for the remaining people are ongoing.