RAF Lakenheath has confirmed that a large bang heard over Norwich yesterday was caused by a brief 'sonic event'.

A spokesman for the airbase said an F-15C Eagle, assigned to the 48th Fighter Wing, was responsible for the incident.

The sonic boom, which occurs when an aircraft travels faster than the speed of sound, happened shortly after 1.40pm and was heard across the city.

A spokesman said: 'We will conduct and investigation and develop mitigation measures. The pilot will receive additional training to prevent this in the future, and will not fly again until this training is complete.

'We offer our sincerest apologies for any disturbance this may have caused, and we will continue to emphasize airspeed restrictions in flight briefings.'

The spokesman said that speed restrictions are in place for aircraft flying over populated areas.

Pilots are meant to stay below Mach .95 (728mph) to prevent them from flying over Mach 1, which is the speed of sound.