Rescuers on Monday said it would be a miracle if they found anyone else alive after a drilling rig sank with 67 people on board in the icy seas off Russia's far eastern coast, although the rig's owner said a raft had been sighted in the water.
The Emergencies Ministry, which usually coordinates rescue operations, declined to confirm a raft had been spotted and it was unclear whether anyone could still be alive after more than 24 hours adrift in the depths of winter.
The Kolskaya rig, working for a unit of state-controlled gas export monopoly Gazprom, sank 200 km (125 miles) off Russia's Sakhalin island, sending a distress signal at 2224 GMT on Saturday.
Of the 67 people on the rig, 14 were saved by vessels accompanying the rig, but 6-metre (20 ft) high waves and temperatures of minus 7 degrees Celsius (19 Fahrenheit) hindered rescue efforts. Rescuers said 16 bodies had been found.
That left 37 people unaccounted for in the Sea of Okhotsk, a vast expanse of water more than twice the size of France.
Until all the people are found the rescue operation will not be concluded, Natalya Salkina, a spokeswoman for federal transport investigators in Russia's far eastern city of Khabarovsk, said by telephone.
Asked how likely it was that anyone would be found alive at sea in such icy temperatures, she said: You can always hope for a miracle.
The seas on Russia's far eastern coast often freeze in winter and such harsh conditions - including freezing air temperatures and biting winds - would leave any survivors badly exposed unless they could find dry cover on the choppy seas.
The slim hopes of finding survivors were raised when the owner of the rig said navy aircraft had spotted a raft floating with people on it although state rescuers played down the information and it was impossible to confirm with the navy.
Aircraft from the Pacific fleet have found a raft. There are people on it, said Andrei Bobrov, a spokesman for the owner of the rig, Arktikmorneftegazrazvedka (AMNGR), a unit of state-owned Zarubezhneft.
Asked whether any of the people were alive, Bobrov said by telephone: It is impossible to say. Have you ever been on an aircraft? You cannot see from that height.
The rig, built in Finland in 1985, was owned by Arktikmorneftegazrazvedka (AMNGR), a unit of state-owned Zarubezhneft, and working on a minor gas production project in the Sea of Okhotsk for a unit Gazprom.
Russian prosecutors have opened a criminal investigation into the incident.
Russia's prize offshore gas and oil fields lie northeast of Sakhalin. Two major offshore projects are already producing oil and gas off the island: Sakhalin-1, operated by Exxonmobil and Sakhalin-2, in which Gazprom has a controlling stake.
(Writing by Guy Faulconbridge and Ludmila Danilova in Moscow, Editing by Tinothy Heritage)