Britain's Royal Air Force launched Typhoon aircraft this afternoon to intercept a civilian aircraft which was causing concern to air traffic control authorities.
The aircraft, a Russian Made Antonov An-26 cargo airliner from Latvia, was safely escorted to London Stansted after being intercepted by aircraft from RAF Coningsby.
An RAF spokesman said: “Typhoon aircraft were launched this afternoon from RAF Coningsby to intercept a civilian aircraft south of London which was causing concern to air traffic control authorities.
“The aircraft was safely escorted to London Stansted.
“To fulfil their quick reaction role the Typhoons were cleared to travel at supersonic speed, any noise disturbance as a result of this is regretted.
“Essex Police now have the lead.”
An Essex Police spokesman said the plane had been intercepted following a loss of communication but on landing it was established that everything was in order.
He said the military jets were deployed as a precautionary measure when the cargo plane was diverted to Stansted Airport.
He said: “This was due to a loss of communication with the aircraft.
“The aircraft landed safely at Stansted Airport at around 5.20pm.
“All three people who were on board have been spoken to by police. It was established that everything was in order and the reason for the short loss of communication was due to a change in airspace jurisdiction.
“Essex Police is not investigating the incident and the aircraft will be able to continue its journey to Birmingham when it’s ready.”
The speed of the aircraft caused a loud bang which was heard across large swathes of Kent at about 4.40pm.
Speculation was rife on Twitter that there had been an explosion or an earthquake and a Kent Police spokeswoman said the force had received a number of reports of a loud bang across the north-west Kent area.
The blast was heard coming from the Dartford area and was also felt in Sevenoaks, Kemsing, Dartford, Faversham, Maidstone and Tunbridge Wells.
Sally Turner tweeted that the explosion had made her house shake in Wilmington, while Jennifer Kenny said: “That bang made my house shake. People have heard it all over Kent.”
The RAF tweeted: “Apologies if we startled you during the successful intercept this afternoon – we only go supersonic over land when absolutely necessary.”
A Soundcloud clip of a warning issued from the RAF Typhoons to the Latvian aircraft said: “Matavia1605 from a Lima Nine Tango Four Seven. I am instructed for Her Majesty’s Government of the United Kingdom to warn you that if you do not respond immediately to my orders you will be shot down.”