People across the city were stopped in their tracks by a deafening roar this morning - but what was it?

The deep rumble lasted for around a minute, mysteriously coming from above and tracking across the sky.

"It sounded like a thunderous din," said one office worker in Brighton after their meeting was interrupted by the sound.

Plane tracking software ADSBexchange revealed the true source of the noise as a fighter jet from the US Air Force.

The plane's route over Europe this morningThe plane's route over Europe this morning (Image: ADSBexchange)

It had taken off from its UK base at RAF Lakenheath this morning bound for Spain when it flew over Brighton at around 10am.

The aircraft, a McDonnell Douglas F-15 Eagle fighter jet, was travelling at around 542 miles per hour at 28,000 feet. It is capable of travelling up to 2.5 times the speed of sound.

Around one hour later, the aircraft's radar turned off as it descended towards the Los Llanos Air Base near Albacete, Spain.

There are no specific rules about noise pollution caused by aircraft - but pilots must be mindful of how close they fly to built up areas by staying above 1,000 feet from the ground.