A sonic boom was heard over Dartford and Essex after an RAF fighter jet scrambled to escort a flight.
Alarmed residents reported an explosion or an "enormous bang" at about 11.45am today (August 15).
It was heard in areas such as Havering, Dartford, Orpington and Erith.
A flight was escorted into Stansted Airport by an RAF Typhoon 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.
Officers determined there was nothing of concern.
A spokesperson for Royal Air Force confirmed: "We can confirm that RAF Quick Reaction Alert Typhoon fighter aircraft from RAF Coningsby were launched today to investigate a civilian aircraft which was not in contact with air traffic control, communications were re-established and the aircraft was safely escorted to Stansted.
"The Typhoons are returning to base"
The full statement from Essex Police says: "A flight has been escorted into Stansted Airport after it lost contact with the ground.
"We were called at around 11.40am today (Friday 15 August).
"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."
This is a breaking news story. More to follow.
