The Royal Air Force has said none of its planes were responsible for what many have called a "sonic boom" over Grimsby.

As reported, the Grimsby Telegraph received many calls from residents who had heard what sounded like a large explosion at about 7pm on Wednesday.

Initial fears that there had been an explosion were quickly allayed and theories turned to the possibility of a sonic boom from a plane.

Initially, these suggestions appeared to be legitimate when it was revealed that the Ministry of Defence (MOD) is currently carrying out a low-flying operation named "Exercise Lightning Force" in the area.

However, when contacted by the Grimsby Telegraph, Squadron Leader Nikki Stacey, based at Headquarters Air Command, said the noise had not been caused by an RAF aircraft, adding there was "nothing reported" from any of the forces' "fast jet units". Gareth Stringer, deputy editor of Global Aviation Resource magazine, said: "A sonic boom occurs when an aeroplane breaks the sound barrier and the noise that you hear is the shockwave of area around the aircraft.

"As far as I am aware, no aircraft should break the sound barrier within ten miles of the coast, but certain atmospheric and weather conditions can mean the sound of the boom can travel further.

"That could explain why something may have been heard inland.

"Being someone who's fascinated with aviation, hearing a sonic boom is something that I would find quite cool, but I can understand why people who didn't know what the noise was would be shocked.

"These things do happen and it is certainly not something that people should be scared about."

Although not confirmed, it appears that some kind of sonic boom is the most popular explanation held by residents who were startled by the noise.

Julie Glover, who lives in Laceby, said: "I heard a big bang and the whole house shook.

"I looked out of the window but all I saw was a plane flying over."

Emma Lingard, of Healing, was tending to her horse in Immingham when the bang occurred.

"I heard a loud clatter on the roof and some pheasants flew off, so I thought it was an animal," she said.

"I jumped and the horse jumped. I walked out of the stable and couldn't see anything.

"When I returned to the car, where my son, Tom, was, he said the car had shook.

"Whatever it was, it was strong enough to shake a parked car."