RAF Typhoons shadowed the Russian Bear planes, as in this earlier incident in September 2014
RAF Typhoons have been launched to intercept two Russian aircraft near UK airspace, the Ministry of Defence has confirmed.
The incident came as Britain hosts a Nato exercise in northern Scotland involving more than 50 warships.
The MoD said the Typhoons, from RAF Lossiemouth, were deployed "after Russian aircraft were identified flying close to UK airspace".
The Russian planes later turned back, flying north past Norway.
BBC defence correspondent Jonathan Beale says the Russian planes were believed to have been "Bear" bomber aircraft.
He says they were first shadowed by Norwegian air force jets before they approached UK airspace.
The MoD did not say precisely where the interception took place.
It is the latest of several similar incidents involving Russian military aircraft flying close to UK airspace.
The Russian defence ministry said its planes had done nothing wrong.
Maj Gen Igor Konashenkov was quoted by Interfax news agency as saying: "Our aircraft operated in absolute compliance with international rules and did not violate anything.
"They simply call it intercept while we just call it escort. This is normal international practice, nothing special. Our aircraft have not violated anything."
Earlier in the day, the Royal Navy deployed HMS Argyll to track three Russian ships, including a destroyer, as they passed through the English Channel.
Tensions between Nato and Russia have risen in recent months over Moscow's role in the conflict in Ukraine and its annexation of Crimea.