
A sonic boom has been reported across parts of the East and South East of England.
The loud bang was heard in Essex, Cambridgeshire, Suffolk, Kent and parts of London at about 11:35 BST.
The RAF confirmed Quick Reaction Alert (QRA) Typhoon fighter aircraft from RAF Coningsby were launched to escort a civilian plane that had lost contact with air traffic control.
A spokesperson said: “Communications were re-established and the aircraft was safely escorted to Stansted. The Typhoons are returning to base.”
A sonic boom occurs when an aircraft travels faster than the speed of sound, generating shockwaves that rapidly compress and decompress the air, producing an explosive noise.
While the speed of sound varies depending on the altitude, it is about 660mph (1,060km/h) at 60,000ft (18,300m).
The sound, often described as an explosion or thunderclap, can be heard over a large area because it moves with the plane, similar to the wake of a boat spreading out behind a vessel.

Essex Police said it began to receive reports of a sonic boom at about 11:40.
A spokesperson said: “A flight has been escorted into Stansted Airport after it lost contact with the ground.
“Contact was re-established with the plane, which had been travelling from Nice, and was escorted into the airport by RAF aircraft.
“On the ground, our officers determined there was nothing of concern.”