An explosion has been heard in parts of Norfolk, as locals took to social media to report their houses shaking from the "sonic boom".
One social media user suggested the sound and subsequent shaking was caused by the Royal Air Force Aerobatic Team, the Red Arrows.
"Just heard a big explosion in Reffley, my windows shook, anyone know what it was or did you hear it from where you were?" one Twitter user asked.
"Anyone in or around King’s Lynn heard it? #explosion #kingslynn
Another Twitter user shared an image of a flight map and said: "Turns out it was Red Arrows creating a sonic boom."
Earlier this year, a sonic boom "like an earthquake" shook UK homes as a Typhoon fighter jet was scrambled into action.
The British Geological Survey said it had received numerous reports of occurrences consistent with those of a sonic origin in Lancashire, as well as Merseyside, Greater Manchester and Cheshire in mid-February.
It said: "Data from BGS seismic networks were examined and signals consistent with a possible sonic origin were recorded at that time.
"British Aerospace confirmed they did have aircraft airborne at the time and two RAF aircraft but cannot confirm at this time if any had gone supersonic."
The Typhoon Apollo11 fighter jet was clocked on flight radar flying in a diagonal path towards Skegness, in Lincolnshire, and over the North Sea.
At the same time, a Boeing Poseidon MRA1 (P-8A) flew over Guernsey and the English Channel - having taken off from Inverness in Scotland.
A sonic boom is a loud noise similar to thunder and is caused by an object moving faster than sound - about 750 miles per hour at sea level.
A spokesperson for the Royal Air Force said: "The sonic boom heard in East Anglia was inadvertently caused by a RAF Hawk aircraft completing a high speed dive as part of an air test schedule, any inconvenience caused to local residents is regretted."
