A plane that lost communication because of a malfunction was escorted to safety by RAF jets, police have said.
People had reported hearing sonic booms across Leicestershire and Northamptonshire at about midday on Saturday.
The plane had two people on board and was flying from Iceland to Nairobi via Southend when it lost contact and had to be escorted to Stansted Airport.
A spokesman for Essex Police said: “A flight has been diverted to Stansted Airport after communications with the pilot had been lost.
“The plane, which had been flying from Iceland to Nairobi via Southend was escorted to the airport by RAF jets and landed shortly before 12.50pm today. Two people, a pilot and co-pilot, were on board.
“Officers engaged with them and carried out inquiries and are satisfied there was a loss of contact due to an equipment malfunction and nothing of any concern.
“The plane and those on board have now been released to continue their journey.”
The Ministry of Defence (MoD) confirmed that Typhoon fighter jets were sent from RAF Coningsby in Lincolnshire to help the aircraft.
A spokesman said: “Typhoon aircraft from RAF Coningsby offered assistance to a civilian aircraft and were authorised to fly supersonic.”
The MoD said it always has jets under a “quick reaction alert” which respond to any aircraft that cannot be identified or is not communicating with either civilian or military air traffic control.
Typhoon fighter squadrons are positioned at RAF Coningsby, RAF Lossiemouth in Scotland and in the Falkland Islands.
Aarondeep Mann, 22, heard the boom in Houghton-on-the-Hill, Leicestershire, and said his first thought was it may have been a gas explosion.
“It was the most random, loud thing we’ve ever heard as we were clearing the boot of the car out,” Mr Mann, a practice manager, told the PA news agency.
“First thoughts were that it could be a gas pipe explosion.
“All the neighbours came out as the houses were practically shaking.”
Plane spotters had earlier suggested that Typhoon jets had been scrambled and were being refuelled in-flight by an Airbus Voyager, the RAF’s only in-flight refuelling plane.
At one point it was being tracked by at least 1,440 people on Flightradar24, a site that tracks aircraft in real time.
Leicestershire Police said : “We have received numerous calls in relation to a large explosion sound heard from various parts of the city and county.
“We like to reassure you that there is no concern however thank you for your immediate response to us.”
A sonic boom is caused when planes fly faster than the speed of sound, which at ground level is about 761mph.
When travelling at this speed, also known as Mach 1, the aircraft displaces the air and creates pressure waves that become compressed and are then released in a shock wave.
As long as the aircraft is flying at Mach 1 it will generate continuous sound waves, known as a boom carpet.
An aircraft flying at 20,000 feet would create a sonic boom cone 20 miles wide.
