Britain scrambled fighter jets on Wednesday after detecting unidentified aircraft approaching its airspace, the defence ministry said.
“Quick reaction alert Typhoon fighters from RAF Lossiemouth, supported by a vogayer tanker from RAF Brieze Norton, have been launched against unidentified aircraft approaching the UK area of interest,” a Ministry of Defence spokesman said.
“We will not be offering any additional detail on this ongoing operation until complete.”
Sky News reported that the aircraft had been detected north of Scotland.
The BBC added that such incidents, known as quick reaction alerts, were not uncommon and involve Royal Air Force (RAF) crews shadowing Russian military aircraft near UK airspace.
The force routinely intercepts and monitors approaching aircraft.
It has said that Russian military aircraft entering the the UK's policed zone of international airspace can pose a hazard to other air users because they often do not talk to air traffic control.
In November, jets were launched in response to Russian strategic bombers.
Officials said at the time the fighters escorted the Russian aircraft out of the area of interest and that the bombers did not enter UK airspace.
