Officials in the Bahamas say three U.S. tourists have died at a Sandals Resort after falling ill. Another had to be airlifted to a hospital for treatment.

The Royal Bahamas Police Force said in a statement that officers were called to the Sandals Resort on the island of Exuma Friday morning after one of the tourists, a man, was found unresponsive in a villa.

On their way to the resort, officers were told two more unresponsive tourists, a woman and a second man, had been found in a separate villa. All three were pronounced dead at the resort, with the woman and second man both showing “signs of convulsion,” local officials said.

A fourth tourist, a woman, was flown to a hospital.

Health Minister Michael Darville said Saturday that some hotel guests went to a clinic Thursday with nausea and vomiting, were treated and left. He said initial investigations indicate it was an isolated incident.

One of the men was Vincent Chiarella of Alabama, his son, Austin, told ABC News. Vincent and his wife, Donnis, were reportedly staying at the resort for their anniversary. Donnis was the woman flown to the hospital, according to Austin, who said he learned of the incident when the U.S. Embassy called him Friday night.

Donnis told her son she fell ill Thursday but felt “she was alright” after leaving the clinic, ABC News reports.

Acting Prime Minister Chester Cooper issued a statement Friday saying that police are investigating and the cause of death was unknown, though foul play “is not suspected.”

“Nothing is more important to Sandals Resorts than the safety of our guests. It is with deep sadness that we confirm the passing of three of our guests at Emerald Bay Resort on May 6, 2022,” a representative for Sandals told Eyewitness News Bahama. “A health emergency was initially reported and following the protocols, we immediately alerted emergency medical professionals and relevant local authorities to provide support and investigate the situation.”

The company said it is cooperating with the investigation.

The Associated Press contributed to this report.