A sonic boom has been heard over London and Cambridge after two RAF jets were scrambled to intercept a private plane.
The aircraft was travelling from Germany and had lost communication with air traffic controllers.
It was diverted to Stansted Airport by the Typhoon jets, which took off from RAF Coningsby in Lincolnshire.
Several people reported hearing a “massively loud bang” in London, Cambridge and other areas in the South East as the fighter plane smashed through the sound barrier at nearly 750mph.
Posting on Twitter, Alistair Broomhead said: “Just heard a loud boom in E12, windows rattled, sounded like an explosion, anyone else in London hear anything? Know what’s going on?”
Another person from Essex, tweeted a doorbell webcam video showing how loud the sonic boom was.
Whilst another user said: “Sonic boom just now over Cambridge! Blew my window off its casement stay and scared the bloomin’ life out of me and the several pigeons outside!”
An RAF spokesperson said: “The RAF can confirm Quick Reaction Alert Typhoon aircraft were launched this afternoon from RAF Coningsby to intercept a civilian aircraft that had lost communications; subsequently, communications were re-established, the aircraft was intercepted and safely escorted to Stansted.
“The Typhoon aircraft were authorised to transit at supersonic speed for operational reasons.”
Typhoons are often deployed to escort aircraft that lose contact with air traffic control or don’t respond to communications.
The plane can go from brakes off to Mach 1.5 (1150 mph/1852 kmh) in two and a half minutes, according to the RAF.
The speed of sound in air varies according to temperature; according to today’s temperature of 5C (41F) in Cambridge, it would have been around 748mph (1204kmh).