(QHA) -

NATO says that it tracked and intercepted four groups of Russian warplanes “conducting significant military maneuvers” in international airspace close to the borders of the European Union during the previous 24 hours, AP reports.

NATO’s SHAPE military headquarters in Mons, Belgium, said, "These sizeable Russian flights represent an unusual level of air activity over European airspace."

It said the planes included strategic bombers, fighters, and tanker aircraft.

They were detected over the Baltic Sea, the North Sea, the Atlantic Ocean, and the Black Sea on October 28 and 29.

Russian bombers flew south all the way to international airspace west of Portugal and Spain.

Norwegian, British, Portuguese, German, Danish, and Turkish fighters were scrambled to intercept and identify the Russian planes.

Planes from the non-NATO nations of Finland and Sweden also responded.

Tensions between NATO and Russia have risen to the highest level since the Cold War, amid ongoing crisis in Ukraine.