The plane, a Tupolev Tu-154 airliner in Russian naval service, was in Estonian airspace for less than a minute, BNS reports, the first such incursion of 2019.

The plane had a functioning transponder and a flight plan had been filed, though it did not enter into radio contact with Estonian air traffic controllers, according to military spokespeople.

No reported aircraft were scrambled from Ämari air base, where NATO air policing duties fly from, though the foreign ministry summoned the Russian ambassador to Estonia Monday over the affair, with the aim of handing them a diplomatic note.

NATO jets at Šiauliai, Lithuania, are often scrambled on interception and escort duties, as Russian military planes often fly close to that country's coastline, though in international airspace, when travelling to or from the Kaliningrad exclave.

Vaindloo is a small island of about 15 acres, which has a nineteenth-century lighthouse, and a Police and Border Guard Board (PPA) station. It is the northernmost point of Estonian territory, and is also a significant breeding sanctuary for birds.