Durdle Door remains closed to the public after three people were seriously injured jumping off cliffs into the sea.
Police, the ambulance service, the coastguard and the RNLI attended the Dorset beauty spot on Saturday afternoon.
Videos posted on social media show people climbing and leaping from the arch at the site, which is 200ft high.
Air ambulances landed at the scene and crowds of people were evacuated from the beach and surrounding cliff area.
Dorset Police confirmed that three people had sustained serious injuries and were receiving medical treatment.
That evening, Dorset Council said Durdle Door and Lulworth Cove would be closed “until further notice”.
On Sunday morning, the council tweeted that the roads to the popular sites remained closed.
But despite this, images taken on Sunday showed people on the beach and even jumping into the sea.
“You will not be able to visit the beaches there and will be asked to turn around if you try and access the villages,” the council said.
It said the measure would be reviewed on Monday but urged people to avoid the area “for now”.
Durdle Door and Lulworth Cove remain closed today along with approach roads to the area.— Dorset Police (@dorsetpolice) May 31, 2020
Please do not travel as you will be turned away. https://t.co/J1VB0DNz9Z
Dorset Police tweeted: “Durdle Door and Lulworth Cove remain closed today along with approach roads to the area. Please do not travel as you will be turned away.”
On Saturday, a post on Poole Police’s Facebook page said the “critical incident” had involved people jumping from the arch of Durdle Door into the sea.
“The arch of Durdle Door is approximately 200 feet in height. Hitting water from that height, roughly 77mph, can be critical,” it said.
“This is further compounded by tides, currents and altering depth of the sea bed. It is NOT an appropriate location for this type of activity.”
Lulworth Coastguard Rescue Team (CRT) posted on Facebook that people had been jumping from the arch “encouraged by the crowds on the beach”.
It said the team’s pagers had sounded at 4.50pm to assist paramedics with a man who had been pulled from the sea after jumping from Durdle Door.
“The beach had thousands of people on it and we thank the majority of people who complied with our shouting to clear a helicopter landing site, a very difficult challenge,” the CRT said.
The team was then made aware of a second casualty, who had also jumped from Durdle Door and staggered back to his friends before “falling very unwell”.
Both men were flown to the major trauma centre at Southampton General Hospital.
A third man, who had also jumped from Durdle Door, was taken to Dorset County Hospital for serious injuries to his torso.
“The remaining beach goers were now asked to leave,” the CRT said.
“The police had to deal with alcohol-fuelled minor scuffles, as well as a small but out of control fire from a BBQ.”
A lady with a suspected broken ankle also received medical attention at the scene before being transferred into an ambulance.
“Upsetting scenes like we and many others witnessed yesterday illustrate how very dangerous tombstoning is. We couldn’t discourage it enough,” the CRT said.
They thanked the “vast majority” of beach-goers who were patient and co-operative in the “very difficult situation”.