The spokesman said the search for the Partnyor was suspended Friday because of darkness but would resume Saturday. There was no ice in that part of the sea.
To the north in the Sea of Okhotsk, two Russian ships remained trapped in thick ice for an eighth day. A third trapped ship has been freed by an icebreaker and was being towed to open waters.
Officials say those three vessels have sufficient fuel and water, and the more than 400 crew aboard are in no danger.