The US military has confirmed that its fighters, together with those of neighbouring Canada, intercepted two Russian Tupolev Tu-95 Bear long-range bombers that has "strayed" to within 15nm (28km) of US airpace in Alaska last week.

The US-Canadian joint North American Aerospace Defense Command (NORAD) and US Air Force Northern Command revealed that the Tu-95s flew close to the North American buffer zone over Alaska, as first reported by the Denver Post newspaper, which serves NORAD's Colorado Springs headquarters.

The Tu-95s were on a training exercise last Thursday when they penetrated the buffer zone, although they stayed within international airspace. Four Boeing F-15C Eagles from the USAF and two Canadian Boeing CF-18 Hornets were scrambled and flew alongside the bombers until the Russian aircraft exited the zone.

However, Russian official claim that the intercepted sorties were a rarity, with most near incursions going undetected.  "During the flights, part of a test of long-range aircraft, the bombers’ crews saw NATO fighters, which were flying parallel to them in their airspace,” the Russian air force says.  “But there were also segments of flights, including close to Alaska, where our aircraft fly unaccompanied,” it adds.

The Russian bombers were likely part of a wider exercise in its Atlantic, Pacific and Arctic regions lasting four days from 26 September involving 70 bombers and the test-firing of 18 cruise missiles.