Russian scientists seeking Lake Vostok lost in frozen 'Land of the Lost'?

A group of Russian scientists plumbing the frozen Antarctic in search of a lake buried in ice for tens of millions of years have failed to respond to increasingly anxious U.S. colleagues -- and as the days creep by, the fate of the team remains unknown.

"No word from the ice for 5 days," Dr. John Priscu -- professor of ecology at Montana State and head of a similar Antarctic exploration program -- told FoxNews.com via email.

The team from Russia's Arctic and Antarctic Research Institute (AARI) have been drilling for weeks in an effort to reach isolated Lake Vostok, a vast, dark body of water hidden 13,000 ft.  below the ice sheet's surface. The lake hasn't been exposed to air in more than 20 million years.

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