The local governor of the Chukotka region said that the marine mammals were trapped about 10 miles south of the village of Yanrakynnot, on the Bering Sea.
“Given the lack of food and the speed at which the water is freezing, all the animals are threatened with exhaustion and death,” Gov. Roman Kopin said in a message to Russia’s transport and emergencies ministries.
The Chukotka government said on its website that the Russian ice-breaking tug Rubin was just two days' sail time away and could bring help to the whales.
The ghost-white Belugas are protected in Russia, and have been championed by Prime Minister Vladimir Putin.
They have been known to become trapped in winter ice in the past, but never in such great numbers.
In 1986, an ice-breaker successfully helped release several trapped Belugas off the coast of Chukotka.