U.S. military officials told Fox News on Tuesday morning that an armed Russian Su-27 fighter jet flew within 5 feet of an unarmed American RC-135 recon plane over the Baltic Sea on Monday.

The officials said the Russian aircraft made “provocative” maneuvers and flew “erratically” after making a rapid approach to the American plane. The U.S. military classified the encounter as “unsafe.”

The officials stated that the Russian jet had air-to-air missiles visible under its wings.

As Fox News observes, there have been a number of provocative encounters between Russian planes and American planes and ships in the Baltic, but few of them featured the Russian pilots making an approach this close. The U.S. military recently completed a training exercise in the Baltics, and of course tensions are high after Russia’s threatening response to the American downing of a Syrian warplane on Sunday.