Estonia also called on Russian troops to leave Ukraine and expressed solidarity with the Baltic state of Lithuania.
NATO member Estonia summoned the Russian ambassador to protest an “extremely serious” violation of its airspace by Russian border helicopters, the foreign ministry said.
A Russian border guard MI-8 helicopter flew over a site in the southeast of the country without permission on June 18, the Estonian foreign ministry and military said on Tuesday.
The incident marks the second time in less than two weeks that Estonia has condemned Moscow’s special envoy in Tallinn.
“Estonia considers this an extremely serious and regrettable incident that will undoubtedly lead to additional tension and is completely unacceptable,” the ministry said in a statement.
“Russia must stop threatening its neighbors and understand that the price of Russian aggression against Ukraine is really high,” the Russian foreign ministry added.
The statement also reiterated its call for Russian troops to leave Ukraine and expressed solidarity with the Baltic state of Lithuania, which Moscow said would be punished for banning the transit of certain goods on the EU sanctions list To the Russian enclave of Kaliningrad.
A senior ally of Russian President Vladimir Putin has told Lithuania that it will suffer if EU-sanctioned goods are barred from entering and leaving Kaliningrad on its territory.
The Estonian military said in a statement that a Russian MI-8 helicopter entered airspace in southeastern Estonia’s Koidula region, not far from the Russian city of Pskov, without permission on Saturday night.
The helicopter remained in Estonian airspace for almost two minutes, the Estonian military said, adding that the helicopter had made no flight plan, its transponder was turned off and it failed to maintain radio contact with the Estonian air navigation service.
The so-called invasion was the second violation of Estonian airspace this year.
Last year, Russian military and civilian aircraft violated Estonian airspace five times, the military said.
Estonia also complained to the Moscow envoy on June 10 that Putin had praised the 18th-century Russian ruler for occupying a city that is now Estonia.
Estonia, Lithuania and Latvia belonged to the Russian Empire before gaining independence after World War I.
In 1940, the Soviet Union annexed the three countries that did not regain their independence until 1991.