Fighter jets were scrambled from an RAF station in Scotland after one or more unidentified aircraft flew close to UK airspace.
The Ministry of Defence (MoD) said the Typhoon jets involved were from RAF Lossiemouth in Moray.
A spokeswoman said they were scrambled as a "precautionary measure against a potential incursion into UK area of interest".
She added: "At no time was there a threat to UK airspace."
The Typhoons later returned to Lossiemouth.
Such incidents in the past have involved Russian military aircraft flying close to UK airspace.
Previous years have also seen Russian warships, including an aircraft carrier and supporting vessels, being shadowed by the RAF and Royal Navy as they sailed off the UK coast.