Residents of Öland, an island off Sweden’s south-east coast, heard a sonic boom as a JAS Gripen fighter jet moved to intercept a foreign aircraft.
“We wanted to look more closely at air activity easy of Gotland,” military spokesman Philip Simon told news agency TT.
“It was in international airspace and did not violate Swedish territory.”
Sweden would not specify the nationality of the aircraft, but Latvia’s military said Nato planes had scrambled to intercept a Russian Su-27 fighter jet and an An-26 military transport plane.
NATO Baltic Air Policing QRA F-16 jets also on 7 OCT scrambled to intercept RU Armed Forces Su-27 over the Baltic Sea.
— NBS (@Latvijas_armija) October 7, 2014
With people in Öland worried about the noise of an aircraft breaking the sound barrier, air force spokesman Kent Löving told local newspaper Ölandsbladet:
”It was in a rush in a live operation and caused a boom at an altitude of 11 kilometres over Öland.”
Löving would not say if Sweden had scrambled more than one plane.
Last week, Swedish intelligence officials released a picture of a Russian jet flying closely beside a Swedish intelligence plane
In September, Sweden lodged a formal protest after Russian fighter jets entered Swedish airspace.