A HUGE bang that sounded like an explosion was a sonic boom caused by RAF planes, police have confirmed.

Thousands of people were woken by what sounded like a "large explosion" in early hours of Sunday morning.

The bang was heard from Brighton to Cambridge at about 4.20am, rocking homes, setting off car alarms and sparking panic.

The Metropolitan Police reassured people when it revealed the bang was caused by RAF planes which were scrambled to intercept an aeroplane flying over the city that lost communications with air traffic control.

"The loud bang was the result of a sonic boom from RAF planes," it tweeted.

"There is no cause for concern."

It is believed two Eurofighter Typhoons taking off from RAF Coningsby in Lincolnshire were the source of the sonic boom.

According to technologist Alp Toker, a Boeing 767-300 from Tel Aviv lost contact with air traffic control at 3.50am, and 10 minutes later at 4am, RAF Coningsby scrambled Typhoons to meet it.# The sonic boom was heard at 4.18am, and at 4.20am the plane safely passed central London and continued its journey.

Depending on the aircraft's altitude, a sonic boom will be heard at ground level two to 60 seconds after it breaks the speed of sound.

The distance from which the boom can be heard is approximately one mile per 1,000 feet of altitude.

Therefore a supersonic aircraft travelling at an altitude of 30,000 miles would cause a lateral boom of about 30 miles.