An American fighter jet from RAF Lakenheath caused a sonic boom heard across mid Norfolk in April, officials have said.
The 48th Fighter Wing F-15 aircraft was flying a training sortie near Watton between 7pm and 10pm on April 17.
A spokesman said that flight plans showed that these passed within 25 miles of the town.
He added: 'Upon review of the flight tapes, it appears one aircraft may have inadvertently gone supersonic momentarily and did not realize it during the flight.
'We will continue to emphasize airspeed restrictions in flight briefings to keep this from happening in the future.
'We offer our sincerest apologies for any disturbance this may have caused.'
Hundreds of people took to Twitter and Facebook after hearing a 'big bang', which some initially mistook for thunder, something hitting their roof or banging on their front door.
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