40,000 Russian troops on Ukraine border

Russian soldiers stand near a tank outside a former Ukrainian military base in Perevalnoye, near the Crimean capital Simferopol, on March 27, 2014.
Russian soldiers stand near a tank outside a former Ukrainian military base in Perevalnoye, near the Crimean capital Simferopol, on March 27, 2014.

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    40,000 Russian troops on Ukraine border

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Russia may now have as many as 40,000 troops near its border with Ukraine. CNN's Karl Penhaul reports.