The Finnish Border Guard is investigating the incident. Defense Ministry spokeswoman Nina Hyrsky told the Finnish news agency STT that Finnish Air Force F-18 jets were scrambled to intercept the Russian aircraft.
She told STT that the violation is suspected to have lasted about two minutes, and that the planes crossed about half a kilometer (0.3 miles) into Finnish airspace. Finland is not a member of NATO. The Su-27 is a combat aircraft widely used by the Russian military to fly from mainland Russia to the nation’s Baltic Sea exclave of Kaliningrad, sandwiched between Poland and Lithuania. The route passes a narrow international air corridor over the Gulf of Finland.
Russia’s Defense Ministry said four Su-27 naval aviation aircraft had conducted a scheduled flight on Tuesday from the northwestern Karelia region to Kaliningrad, without violating the airspace of other countries.
“The flight proceeded along the earlier-agreed route and the crews of the Russian planes were in constant contact with air traffic control posts,” the ministry statement said, as quoted by TASS news agency.