Most of the installations of Russia's North Pole-32 research station sank overnight Wednesday, when the ice below it first cracked and then disintegrated.

None of the 12 researchers posted to the station was hurt and all took shelter in the few structures that did not sink in the icy water, officials said.

"All of a sudden around 5:15 pm (1415 GMT) a huge wall of ice appeared that kept growing and growing," station chief Vladimir Koshelyev told Rossia television website.

"First they were three meters (yards) high, then five, then seven and finally over 10," he said. "In the course of a half hour they practically swallowed up 90 percent of the station, leaving only two small houses."

The researchers, all experienced polar hands, have taken shelter in the two houses with food and emergency supplies to last about five days, he said.

The researchers alerted border guards to the accident via radio and three helicopters have been prepared to pluck the scientists off the ice.

The choppers were Friday due to fly out to the station, where wind is howling up to 50 kilometers (30 miles ) per hour, said Artur Chilingarov, a deputy speaker of parliament and former Arctic explorer who is coordinating the rescue effort.

"Don't worry... We'll get you off so you can return to the motherland," Russian television showed him as telling the researchers on the telephone from his State Duma office.

The station, set up in April 2003 to study climate change, has travelled some 3,000 kilometers atop the ice floes since then and is currently some 700 kilometers (440 miles) from the North Pole in the Nansen Basin, news reports said.

The station, Russia's first since the Soviet Union fell apart in 1991, was due to complete its work by March 20.

TERRA.WIRE