RAF jets have been scrambled to intercept Russian bomber planes that have spent more than five hours skirting the edges of British airspace.
The Independent understands the Russian Tu-160 "Blackjack" bombers entered the UK's area of interest from the north east at around 10am, flying between the Shetland and Faroe islands, then flew down the west coast of Ireland and over the Bay of Biscay.
French and Spanish aircraft took over the interception but the two planes then turned around to head back towards Russia, flying back into the British military's "patch" while heading north.
The bombers passed the coast of the Outer Hebrides shortly after 3pm.
A Royal Air Force spokesman said: “We can confirm that quick reaction alert Typhoon aircraft from RAF Lossiemouth and RAF Coningsby scrambled to monitor two Blackjack bombers while they were in the UK area of interest. At no point did the Russian aircraft enter UK territorial airspace.”
The Typhoons were supported by a Voyager air-to-air refuelling aircraft from RAF Brize Norton for the mission, which lasted several hours.
The incident is the latest RAF deployment in response to Russian military manoeuvres, following the tracking of Russian warships that passed through the English Channel on their way to bomb Syria last year.
Russian bombers have skirted British airspace on numerous occasions, including last February when two Russian Blackjack bombers were escorted.
Vladimir Putin has been accused of Cold War-style “brinkmanship” over a series of similar incidents with Nato aircraft across Europe, with more than 100 Russian planes intercepted in 2014 alone.[size=1.3]Russian airstrike 'accidentally' kills Turkish soldiers fighting IS