RAF jets intercepted a Russian spy plane close to Estonian airspace in the latest sign of tensions between Moscow and Nato.
The two Typhoon jets, operating as part of Nato's Baltic air policing mission, were launched to intercept the Ilyushin IL-20 Coot surveillance and reconnaissance plane.
The Ministry of Defence said the incident took place in international airspace over the Gulf of Finland at lunchtime.
Nato has been protecting the Baltic skies since 2004, when Estonia, Latvia and Lithuania joined the alliance.
The mission was stepped up last year "in response to Russia's aggression against Ukraine", Nato said.
Moscow's support for separatist forces in Ukraine has put the relationship between Vladimir Putin and the West under intense strain, with British jets scrambled to intercept Russian aircraft near the UK in recent months.
Last month RAF f ighters and a Royal Navy warship were called into action as Russian bombers and vessels passed close to the UK.
HMS Argyll was deployed to monitor a destroyer and two other ships from the country as they passed through the English Channel, while Typhoons were sent from RAF Lossiemouth in Scotland after two Russian Bear aircraft were spotted flying close to UK airspace.
Defence Secretary Michael Fallon said the incident in the Baltic showed the importance of the UK's involvement in the Nato mission.
He said: " Air interceptions like this underline the vital importance of the UK's contribution to the Baltic air policing mission.
"The UK's role in the protection of Nato airspace and the involvement of our personnel in the Estonian exercise currently taking place demonstrate our commitment to Nato's collective defence and the value of our armed forces' expertise in improving the military capabilities of our allies."