Three men have died after being pulled from the sea at Camber Sands beach.
Emergency services were called after three people were found in need of urgent medical aid at the coast near Rye, East Sussex on Wednesday afternoon.
Beach goers were urged to stay out of the water as medics helped the men, who have yet to be identified.
It is understood reports of a person in the sea were first received at 2.10pm, a second person was then discovered in difficulty at 2.20pm and a third person was pulled form the sea 15 minutes later.
A Sussex Police spokesman said: "The three men sadly died despite efforts to save them."
The Lydd and Lee-on-Solent-based UK Coastguard search-and-rescue helicopters also attended the scene, along with an air ambulance.
An RNLI lifeboat from Rye and Coastguard rescue teams were also in attendance.
Natalja Taylor, 30, who was on a day-trip at Camber Sands with her husband on the hottest day of the year, said police were driving up the beach with a loud hailer calling on people to stay out of the sea.
She said: "We saw three people being pulled out of the water. I think the people who rescued them were regular people, not emergency personnel.
"Police drove on to the beach with a loudspeaker, telling people not to go into the water until further notice. They also taped off a huge chunk of the beach so no-one could get near it.”
It is the second serious incident to take place recently at Camber Sands.
In July, a 19-year-old Brazilian Gustavo Silva da Cruz died after getting into difficulty while swimming in the sea.
A 35-year-old man and his 17-year-old son, not connected to Mr Da Cruz, also got into difficultly in the water.
Chief Superintendent Di Roskilly said: "We are working with Maritime and Coastguard Agency, Royal National Lifeboat Institute, South East Coast Ambulance and Rother District Council to clear the beach and encourage people to come out of the sea while we are investigating this incident.
"We are also asking people to stay away from Camber for the afternoon and evening to assist emergency services in managing this incident.
"This has been an incredibly tragic situation and very traumatic for those who were there on the beach at the time. At this stage we do not know who the men are and are doing all we can to establish their identities."
Additional reporting by Press Association
