NATO says Russia's growing military presence in the skies above the Baltic region is unjustified and poses a risk to civil aviation.
NATO Secretary General Jens Stoltenberg said in Tallinn on November 20 that the aircraft regularly fail to file flight plans or communicate with air controllers and also fly with their transponders off.
Speaking at the Amari air base, he said alliance fighters have intercepted planes more than 100 times in the Baltic region alone so far this year, a threefold increase over 2013.
He did not say how many of the intercepted aircraft were Russian.
Stoltenberg also said that, overall, NATO aircraft have conducted 400 intercepts to protect the airspace of its European alliance members in 2014 -- an increase of 50 percent over last year.