Rescue helicopters have recovered 4 of 26 people from a cruise ship missing on the Shiretoko Peninsula.

The Japan Coast Guard said it found four people missing from a cruise ship with 26 people missing in the frigid waters of northern Japan. But it is unclear if the four are still alive.

A police helicopter spotted three near the tip of the Shiretoko peninsula early Sunday morning, and about 30 minutes later, a Coast Guard plane spotted a fourth in the same area, the Coast Guard said.

The condition of the four is unknown, and it is unknown whether they were on land or at sea when they were found.

“They are being transported for medical treatment,” a Coast Guard spokesman told AFP. “Other details are not yet known.”

NHK public television said the four were unconscious.

NHK footage showed one of those rescued arriving by helicopter and being transferred to an ambulance on a stretcher, while rescuers held up blue plastic shields for privacy.

An undated photo published by Jiji Shimbun on April 23, 2022 and taken from the website of operator Shiretoko Cruise shows the sightseeing boat “Kazu I” in Hokkaido Prefecture, northern Japan [EPA-EFE/Shiretoko Tour Boat]

Sunday’s rescue came after an intense search of nearly 19 hours, including six patrol boats, several planes and divers. The Coast Guard said the search continued overnight.

The Coast Guard said the Kazu 1 made an emergency call early Saturday afternoon, saying the bow had entered water and that it had begun to sink and tilt as it sailed off the west coast of the Shiretoko Peninsula, off the northern island of Hokkaido.

It was last heard about two hours later when it contacted its operating company to say it was tilted at a 30-degree angle, Kyodo news agency reported.

The crew said everyone on board was wearing life jackets, the media said.

There were 24 passengers and 2 crew members on board. Two of the passengers were children.

The average sea temperature in April in Shiretoko National Park, a UNESCO World Heritage Site in 2005, was slightly above freezing.

Sightseeing cruises in the area are popular with tourists looking to spot whales, birds and other wildlife, as well as ice floes in winter.

Prime Minister Fumio Kishida, who was attending a two-day summit in Kumamoto, southern Japan, canceled his trip the next day and returned to Tokyo. He told reporters in the early hours of Sunday that he instructed officials to “do whatever they can to rescue.”

The cause of the accident is still under investigation, but experts suspect the ship ran aground and was damaged.

Large waves and strong winds were reported in the area around noon Saturday, according to the local fishing cooperative. Japanese media reported that the fishing boat had returned to port by noon due to bad weather.

The NHK said a warning was issued for high waves as high as 3 meters (9 feet).