Hundreds of people have heard a big explosion in Leicester this afternoon amid reports that RAF Typhoon aircraft were scrambled to intercept a jet.
Some residents felt the ground shaking following the explosion in the city, with a person living in North Leicester saying the loud noise "rocked the house".
The explosion - that some believe may have been a sonic boom - was also felt in Northampton and North Oxfordshire, where a person described it as a "massive bang".
A person living near RAF Croughton in Northamptonshire also reported hearing the loud bang.
The RAF's Airbus Voyager, the air force's only in-flight refuelling plane, was being tracked by at least 1,440 people on Flightradar24 - a site that tracks aircraft in real time.
A sonic boom is a loud sound similar to an explosion. It's caused when planes fly faster than the speed of sound, which at ground level is around 761mph.
Miles Pulsford, who lives in Leicester, said the loud noise just before 12.10pm today "shook the house" and sounded "like a bomb had gone off".
He told the Mirror: "I looked outside and saw loads of birds flying around the trees. A passerby also said she heard it, and her dog jumped."
An aviation expert said on Twitter that RAF Typhoons scrambled to intercept a Dash 8 aircraft heading towards London after it experienced radio failure.
Aviation Highlights tweeted: "The fighters were reportedly supersonic on their way south from RAF Coningsby."
The flight was escorted to Stansted Airport in Essex by RAF jets, reports Essex Live.
Essex Police said the flight was diverted after communications with the pilot had been lost.
Stacy Brookfield, who lives in Woodford Halse, Northamptonshire, said the noise made her "jump" from her chair.
Mark Taylor said he was going to let his dogs out when he opened the door and thought something had exploded.
He said: "Our windows rattled and roof shook."
Courtney North, 25, said her whole flat in Stocking Farm, Leicester, shook after the explosion.
She said she felt scared and her young children were frightened too.
Bernie Tiller said the explosion "made all the windows rattle", as he added: "I have heard a sonic boom before and this was very much the same."
Jacquire Lavelle said the explosion was also heard in Fritwell, Oxfordshire, with neighbours confirming they heard it as far as Abingdon.
Another reader, Sadiah, told the Mirror she was in the kitchen and felt like her house was moving, as if it was an earthquake.
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."
When planes travel faster than the speed of sound, also known as Mach 1, the aircraft displaces the air and creates pressure waves that become compressed and 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.
A spokesperson for Essex Police said: "A flight has been diverted to Stansted Airport after communications with the pilot had been lost.
"The plane was escorted to the airport by RAF jets and landed shortly before 12.50pm today (Saturday 4 March). Officers are engaging with the pilot and enquiries are ongoing."
A Ministry of Defence spokesman said: “Typhoon aircraft from RAF Coninsgby offered assistance to a civilian aircraft and were authorised to fly supersonic.”
