SPECULATION ran rife across the area after a fighter jet flew over.
It was heard across West Sussex on Wednesday and people turned to Facebook to speculate about what aircraft it was.
Keith Manaton from Shoreham Beach, who photographed the jet in Hove, said: “It had twin tails, could have been a F18 Hornet or such like.”
Darryn Burton, writing on the Shoreham Herald Facebook page, said: “I thought we were under attack!”
Gary Baines, chairman of the Friends of Shoreham Fort, said: “I saw it over Shoreham Fort. Then it came back later, too.”
Many residents said they heard the aircraft in Shoreham and Southwick but did not get a chance to see it.
Lisa Strevens said: “It flew over my house in Roman Way, Southwick, twice. Too fast to see it though.”
Finally, the truth was revealed - the aircraft was an American F-15, making two passes.
Suzanne Harper from 48th Fighter Wing said they had received a number of messages via social media about the jets.
Capt Emily Grabowski explained the jet was one of the US Air Force’s F-15s from RAF Lakenheath in Suffolk.
“What everyone saw was a practice diversion at Southampton, which basically means it practised an approach at the airfield without landing,” she said.
The air space in the area was appropriate for the low-altitude training needed.
US Air Forces in Europe at RAF Lakenheath is a major command and the 48th Fighter Wing’s mission is to provide worldwide responsive combat air power and support.