The Royal Air Force (RAF) scrambled jets from two of its airbases to "monitor" two Russian bomber planes that had flown close to British and Irish airspace.
An RAF 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 jets in question are thought to be Russian Tu-160 "Blackjack" bombers and they flew into the UK's area of interest between the Faroe islands and the Shetlands north of Scotland.
The bombers, which can carry long-range nuclear cruise missiles, then flew along the west coast of Ireland and south towards the Bay of Biscay.
It is not clear if the planes were armed.
A spokesperson for the Irish Aviation Authority told the Independent: "On Thursday 9th February 2017, the Irish Aviation Authority (IAA) monitored the activity of aircraft transiting Irish Controlled airspace. These aircraft were reported to be Russian Military aircraft.
"At no time did these aircraft enter Irish sovereign airspace. The aircraft were operating in Irish controlled airspace which extends 256 nautical miles off the west coast of Ireland, at no time did the aircraft infringe Irish sovereign airspace which extends to 12 nautical miles off the Irish coast.
"There was no safety impact to civilian traffic operating in Irish controlled airspace."