Sussex Police cordoned off the beach between New Parade East and The Crab Shack, late this morning. Shortly before 1pm, a spokesman confirmed it was soon to be joined by a bomb disposal team.
Stephanie Kalber, who was visiting Splashpoint leisure centre at the time of the incident, said the children's pool was closed.
On Twitter, she wrote: "We were evacuated from Splashpoint. Police asked them to close the kids pool due to the risk of the glass windows facing the seafront."
Splashpoint has been approached for comment.
Providing an update on the incident at 2pm, the police spokesman said an unidentified item has been removed from the beach by the Explosives Ordnance Disposal (EOD).
He added: "We don't know what it is, at this stage, but we don't think it is a bomb. It has been taken away by EOD."
On Twitter earlier this afternoon, resident Mark Goulding, who lives on the seafront, wrote: "Beach and promenade between New Parade East #Worthing and The Crab Shack #splashpoint have been cordoned off by police due to WW2 bomb washed up on beach."
Updates to follow as and when we get them.