Six patrol vessels and four aircraft are involved in the search after the sightseeing boat goes missing in rough waters.
No survivors have yet been found after a tour boat with 26 people on board issued a distress call that it was sinking off Japan’s northern island of Hokkaido.
Six patrol vessels and four aircraft were involved in the hours-long search on Saturday after the boat went missing in rough waters off northern Japan, the coast guard said.
As of 10:30pm (13:30 GMT), some nine hours after the initial distress call was sent, officials said the search was ongoing.
The 19-ton Kazu 1 made an emergency call early Saturday, saying the ship’s bow had flooded and was beginning to sink and tilt when it was travelling off the western coast of the Shiretoko Peninsula on Hokkaido island.
High waves and strong winds were observed in the area at about noon, according to a local fisheries cooperative, and fishing boats returned to port because of the bad weather.
A warning for high waves of up to 3 metres (9 feet) was issued, Japan’s public broadcaster NHK reported. Average April sea temperatures in Shiretoko National Park are just above freezing.
The crew also said those on board were wearing life jackets and the boat was keeling at a 30-degree angle, NHK said. There were 24 passengers, including two children, on board and two crew members.
The tour boat has since lost contact.
A coast guard official told AFP news agency rescuers had “set up a task force to tackle the incident” and look for the missing, but declined to confirm any other details.
A staff member at the vessel’s operator, Shiretoko Pleasure Cruise, said he could not comment as he had to respond to calls from worried families of the passengers.
According to its homepage, the ship holds 65 people. Tours around the Shiretoko area usually last about three hours, according to the tour company.
The Shiretoko National Park is listed as a UNESCO World Heritage site and is famous as the southernmost region to see drifting sea ice. Sightseeing includes nature and animals such as whales, dolphins and the brown bear.