Police are responding to a “hazardous material incident” after people reported having sore eyes and vomiting at a seaside resort.
A two-mile cordon has been set up on Worthing seafront. Social media users reported being evacuated from the pier, but this has not been confirmed by Sussex Police.
People were urged to stay away from the area and shut windows and doors.
Officers said the symptoms had affected “a small number of people”.
Kite surfing instructor Christine Johnston said she was about to start a lesson near Windsor Road when she was told to leave the beach.
“The beach patrol buggy came and told us to leave the beach immediately,” she said.
“They had their faces covered, one with a dust mask and the other using their clothing.”
She added: “It seemed quite serious. We got the impression there had been some kind of incident or something in the air.
“They said several people had been hospitalised.
“I did feel like my eyes were itchy. It was a bit more than hay fever. I went and rinsed my eyes and I feel fine now.”
The cordon is in place along Marine Parade between Grand Avenue and Windsor Road.
Sussex Police said investigations were ongoing and they would release more details “as soon as we are able to”.
The force said two people were taken to hospital, before being discharged and advised to “go home, wash their clothes and have a shower”.
Police added: “Anyone else affected is advised to do the same – and use copious amounts of water to wash your eyes.”
In August 2017, about 150 people attended hospital reporting sore eyes and vomiting after a chemical haze drifted over Eastbourne.
An investigation by the Department for Environment, Food and Rural affairs concluded the gas cloud was likely to have come from the Channel.
It said: “It seems most likely that the source of the gas was a ship, lost cargo, or possibly a wreck.”