A loud explosion was heard in central Brighton just after midnight – but its source is still a mystery.
Residents as far afield as Preston Park and Elm Grove have taken to social media to voice their concerns.
The Sussex Police helicopter patrolled the sky over Fiveways and towards St Peter’s Church after the incident and there were reports of heightened police activity in those areas.
But officers were not able to discover what caused the bang.
A spokesman for Sussex Police said: “At around 20 minutes past midnight on Monday (26 June) police received a report of a loud bang in the Preston Road area of Brighton.
“Checks were made to see if it might be associated with overnight engineering works on the railway or other likely sources of detonation but nothing was found.
“There were no reports of injury or damage to property.”
According to reports, the explosion seemed too loud for a firework and startled many birds in the area. Windows were said to be rattled as far apart as Preston Village and Woodingdean.
Speculation is rife, with suggestions of a military jet breaking the sound barrier out to sea or even a small comet exploding high in the atmosphere.
Not since the mid 70s, when the supersonic Concorde aircraft was found to be responsible for large explosion type sounds over Brighton and Hove has the city experienced such a phenomenon.
Maybe soon the source of the explosion will come to light – or perhaps it will remain another of Brighton and Hove’s quirky mysteries.