Estonia's foreign ministry condemned the incursion as "brazen". It said three Russian MiG-31 fighter jets entered the airspace of a NATO member "without permission and remained there for a total of 12 minutes" on Friday over the Gulf of Finland.
NATO spokesperson Allison Hart said the military alliance "responded immediately and intercepted the Russian aircraft” and called it "yet another example of reckless Russian behaviour and NATO's ability to respond.”
The Russian military has not publicly commented on the issue.