Russia reportedly seizes a Ukrainian military base, begins air drills in Crimea

For additional information from a second source, please see the following article: Report: Russian soldiers storm Ukrainian military base in Crimea

Armed men believed to be Russian seized a Ukrainian military base in Crimea Friday, triggering a standoff but no gunfire in the latest incident of escalating tension in the flashpoint peninsula.

The move followed reports earlier in the day that Russia had begun large-scale air defense drills.

Witnesses say Russian troops broke through the gate of a missile defense base with a military vehicle, trying to break into a command post, but no shots were fired, Interfax Ukraine reported.