The Ukrainian air force scrambled a lone SU-27 interceptor aircraft to intercept Russian fighter jets that violated Ukrainian airspace twice early Monday morning.
The Ukrainian Defense Ministry said that the Ukrainian crew "demonstrated the professionalism and moral-psychological endurance to resist provocation."
The ministry did not say how many Russian aircraft had been spotted or what model they were, Interfax reported.
This is the latest in a growing series of reports about the Russian military violating Ukrainian territorial sovereignty. The Ukrainian border service reported that on Feb. 28 at least eight Russian IL-76 planes and seven attack helicopters crossed into Ukrainian airspace and illegally landed in Crimea without proper authorization from Ukrainian authorities.