Russian military aircraft circled HMCS Toronto in an “unnecessarily provocative” move over the Black Sea, the minister of national defence said Monday.

Two Russian fighter jets and a Russian surveillance aircraft “buzzed” the Canadian frigate on Sunday, CTV’s Ottawa Bureau Chief Robert Fife reported.

One of the fighter jets came within 300 metres of the ship. HMCS Toronto locked its radar weapons system on the Russian aircraft, but took no further action because the planes were unarmed, sources say.

Although the move did not pose a threat to HMCS Toronto or its crew, Russia’s actions were “unnecessarily provocative and risk escalating tensions even further,” the office of Defence Minister Rob Nicholson said in a statement.

HMCS Toronto is currently operating in the Black Sea along with other NATO warships. At the time of the incident, the ship was en route to Operation Sea Breeze, a three-day, U.S.-led exercise with the Ukrainian navy.

The Black Sea borders Ukraine, Russia, Turkey and Romania, along with other countries.

One naval expert says it’s not surprising that Russia sent warplanes since it considers the Black Sea its backyard.

“There is always an opportunity for something stupid to happen and somebody get in too close or somebody do something provocative that would actually escalate the incident and get quite dangerous,” Hugh Williamson told CTV News.