A family of killer whales has again become stranded in a silted estuary in Russia's far east just hours after researchers helped the two adults and two calves into deeper water, the emergency ministry said on Thursday.

Russian researchers and volunteers spent all of Wednesday dousing the killer whales with water after they beached in the estuary on the Kamchatka Peninsula and when the tide rose managed to get the orcas to deeper water.

But on Thursday, the family was again stranded.

"This morning they swam away from the shallow water towards the open sea," the emergency ministry said.

"Sadly, the animals could not find the narrow exit from the estuary and at low tide they found themselves in shallow water again."

One of the orcas was shown by Izvestia lying in shallow water on its side and was distressed.

The newspaper cited an unidentified source as saying the family group might be refusing to swim into the ocean because one of the group was injured and so was unable to go into deeper waters.

Orcas, or killer whales, belong to the sub-order of toothed whales but are also the largest member of the dolphin family, according to Whale and Dolphin Conservation.

Reuters

Rescuers and volunteers try to save killer whales stranded at the mouth of the Bolshaya Vorovskaya River at the coast of the Sea of Okhotsk, on the Kamchatka Peninsula, Russia October 2, 2024. Head of the Sobolevsky Municipal District of the Kamchatka Region Andrei Vorovskiy via VK/Handout via REUTERS

Killer whales get stranded again in Russia's far east