OTTAWA—The Defence Department says Canadian fighter jets in Romania have intercepted a Russian military aircraft that was approaching NATO airspace over the Black Sea.

Two CF-18s were scrambled Thursday after NATO detected the Russian SU-27 Flanker operating near Romania, where Canada has had five fighter jets and 135 military personnel.

A department statement says the Canadians shadowed the Russian aircraft until it left the area.

The incident marks the first time Canadian fighter jets have been scrambled since arriving in Romania in August as part of a NATO-led effort to defend the alliance’s airspace.

The Canadians will remain in the country until December.

NATO allies have stepped up their monitoring of Russia’s military activity in Eastern Europe since Crimea was annexed in 2014, sparking fears of further Russian aggression in the region.