A Japanese tourist boat carrying 26 people is believed to have sunk in rough waters - with no sign of survivors hours later, the coastguard said.
The 19-ton Kazu1 was cruising off the scenic Kashuni Falls, near the tip of the Shiretoko Peninsula in the northern island Hokkaido, when it sent a distress call on Saturday afternoon.
Six patrol boats and four aircraft have been launched amid a major search after the report came in around 1.15pm local time (5.05am UK).
