Ministry of Defence issue statement over sonic boom
People reported hearing an explosion in Leicestershire, Northamptonshire and Oxfordshire
The Ministry of Defence says RAF Typhoon fighters were authorised to fly supersonic to help a plane in distress earlier - causing a sonic boom over parts of the country.
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.
People had reported hearing a large bang across Leicestershire and Northamptonshire at about midday on Saturday.
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.
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.