You're reading: Chicago Tribune: Russia gives Ukrainian forces in Crimea ultimatum to surrender

Russia's Black Sea Fleet has told Ukrainian forces in Crimea to surrender by 5 a.m. on Tuesday or face a military assault, Interfax news agency quoted a source in the Ukrainian Defence Ministry as saying.

The ultimatum, Interfax said, was issued by Alexander Vitko, the fleet's commander.

The ministry did not immediately confirm the report and there was no immediate comment by the Black Sea Fleet, which has a base in Crimea, where Russian forces are in control. 

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