Around 10 killer whales found trapped in drift ice off Japan's northernmost main island of Hokkaido likely escaped as they appear to no longer be there, local officials said Wednesday.

"As the gap in the drift ice started to open, it's likely they escaped," said an official of the town of Rausu after the animals could not be spotted through binoculars Wednesday morning.

Photo shows a pod of killer whales trapped in drift ice in waters off Rausu, Hokkaido, on Feb. 6, 2024. (Copyright Wildlife Pro LLC)(Kyodo)

On Tuesday, a pod of killer whales that included calves was seen from a small gap in the water's surface around 1 kilometer from the coast, according to the town.

The town could not carry out a rescue operation as its vessels were unable to get to the animals, it said, after the space between the drift ice may have been frozen and blocked by low temperatures.

In a similar case in Rausu in February 2005, a number of killer whales died after around 10 of them became trapped in drift ice.

The town of Rausu is located on the Shiretoko Peninsula in eastern Hokkaido. Shiretoko is recognized as a World Natural Heritage Site by the U.N. Educational, Scientific and Cultural Organization.

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Around 10 killer whales trapped in drift ice off Hokkaido