Russian fighter jets were intercepted off the coast of Alaska on Thursday morning.

The aircraft, two Cold War Bear bomber jets and two Su-35 ‘Flanker’ planes, were detected in international air space some 50 miles southwest of Chariot early in the morning, Fox News reports. 

They were intercepted by two U.S. Air Force F-22 stealth fighter jets which were performing a routine patrol when they came across them.

It is the latest in a sequence of moves which point to the simmering tension between American and Russian forces since the US launched an air strike on a Syrian air base last month.

The Bear bombers were brought in to service in 1956 and were  an ominous threat to Western allies during the Cold War, regularly flying over the coast of Cornwall as well as hovering near US airspace.

Last month, the bombers flew off the coast of Alaska for four days.

Thursday’s incident was the first time the Bear bombers have been spotted near Alaska with a Flanker fighter jet escort.