"Two Spanish F-18 jets assigned to NATO’s Baltic Air Policing mission scrambled from Estonia's Amari Air Base. Finnish jets also scrambled to intercept the aircraft," said NATO in a statement released on Tuesday.

It noted that the Russian aircraft were identified two MiG-31 jets and one Antonov AN-26 transport plane.

NATO also announced that its planes had briefly violated Finnish airspace while carrying out the intercept maneuvers.

“In handing over the intercept to the Finnish jets, the Spanish jets accidentally entered Finnish airspace…NATO’s Air Command has explained the incident to the Finnish Air Operations Center to improve future coordination,” said NATO spokesman Dylan P. White.

Russia’s Defense Ministry said that the Russian planes were “carrying out a training flight over the neutral waters of the Baltic Sea… in strict accordance with the rules of the use of airspace, without violating the borders of foreign states.”