A loud bang heard across a large part of England on Thursday night was from a sonic boom caused by a Typhoon jet, the Ministry of Defence said.
Police and fire services in the West Midlands were inundated with phone calls shortly after 6pm from concerned members of the public, mainly in the Coventry area, who reported the noise.
Many people on Twitter and other social networking sites confirmed they had also heard the noise, some as far as Swindon and Oxfordshire.
A spokesman for the Ministry of Defence confirmed the bang was caused by a Typhoon fighter aircraft.
Mystery surrounded the source of the noise for more than an hour, with reports of it having been heard in Bath, Swindon, Coventry, Rugby and Oxford.
Speculation about what could have caused the noise ranged from a large explosion to a tremor under the earth.
Many people on Twitter reported doors and windows shaking, while others thought there had been an underground explosion.
It is the second time this year that a sonic boom has been created by a Typhoon aircraft.
In January, the MoD confirmed that a loud noise heard by people across the North of England was caused by an RAF fighter jet breaking the sound barrier.
An MoD spokesman said two Royal Air Force Typhoon aircraft had been authorised to go supersonic after a small civilian helicopter had emitted an emergency signal.
They were already in the air and on their way to the helicopter by the time the pilot realised he was transmitting on the wrong frequency and switched to the correct one.
The MoD response was standard procedure after receiving such a signal, the spokesman added.
An MoD spokesman said: "We can confirm that a small civilian aircraft was transmitting inadvertently on an emergency frequency at approximately 1810.
"Two typhoons from the Quick Reaction Alert (QRA) responded accordingly and authorisation was given from them to go supersonic, which resulted in the sonic boom.
"There was no actual threat to the civilian aircraft and they soon rectified their mistake."
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