Thunderous American bombers disturb our evening after flying over the West Midlands

The thunderous noise came early in the evening and then disappeared as quickly as it came.

It led to speculation on social media that UFOs were about. Others thought a huge lorry had rumbled past or it was an earthquake.

The answer, it appears, lies with the US air force and two USAF B1-B Lancer bombers that were passing as part of a military exercise.

The West Midlands is believed to have been part of the flight path as the two aircraft made a circuitous route to and from the Back Sea, where they were deployed to support Bomber Task Force Europe 22-1. They were also involved in a Romanian and Polish Nato Air Policing mission over Romania.

The roar could be heard at around 6.45pm on Tuesday across the West Midlands, Shropshire and Staffordshire, but was particularly intense in Wolverhampton. It became the talk of the Penn Online Facebook page, with Jack Daniel asking: "Did anyone else hear that strange noise just like a low flying jet plane going over but it was staying in one place then it just stopped dead?"

Nick Brindley replied: "Yes heard them as clear as day, above the clouds. On full throttle then throttled off for several minutes then heard them throttle up again over Shropshire way."

Fiona Whitehouse added: "It was a crazy sound. They were above the clouds so couldn’t see them but wow scary." And Jayne Thomas replied: "It was the bit when it just stopped that freaked me out. We often get Chinook helicopters here landing at the Royal School and they are noisy but that was something else – especially when it stopped."

Paul Rooke said: "My kid said she thought it earthquake. It was as loud as hell."

The aircraft are based at RAF Fairford in Gloucestershire. A USAF spokesman said: "Two B-1s executed a counter maritime mission while integrating with NATO allies and partner forces to enhance interoperability."