Some people in  Lancashire, including Ainsworth, had a rude awakening in the early hours of Wednesday morning (August 9) after hearing a loud noise outside.

The RAF has now revealed the cause of the loud noise to be a military helicopter.

The noise, which was heard at around 3am, disturbed residents in various areas across Lancashire, with many likening the noise to a “freight train” or “the start of World War Three”.

The helicopter's flight path took it over Radcliffe and East Lancashire.

One posted on Ainsworth Community Group: "It was so loud.

"Just found on flight tracker, it was a Boeing HC.6. Flew right over my house."

On social media another said: “Yes I heard it in Mellor. It was right over our house… it was a bit scary to be honest."

Another said: “The noisy thing, I thought it was going down!

“Thought it was landing on the close it was that loud."

“It vibrated my windows,” said another.

A fifth person said: “I heard it in the distance and thought someone was mowing their grass."

Another said: “I thought that thing was landing in my garden in Ribchester, the noise was incredible!

“The dogs were terrified and I [thought] it was the police with an escapee in my garden."

"I thought it was the start of World War Three," said another.

Holly Bowden shared a video of the helicopter and you can hear it as it flies over.

The RAF has confirmed that the helicopter was a Chinook helicopter, on a routine training operation from RAF Odiham.

An RAF spokesperson said: "RAF Chinooks from Seven Squadron at RAF Odiham. [It] completed routine operational training and was low flying in north west England last night.

“For some of the aircrew this training was the final part of their training in which they were assessed and achieved the standards required to become ‘mission qualified’ ready for global operations."

Chinooks have been spotted several times across Lancashire, in recent years.

Keen photographers captured the helicopters.

According to the RAF website, the Chinook is an “extremely capable” and “highly versatile” support helicopter that can be operated from land bases or ships.

It may be armed and is fitted with self-defence equipment.

The aircraft is primarily used for trooping, resupply and battlefield casualty evacuation.