CNN  — 

An American woman hospitalized Friday in the Bahamas, where three other Americans died of unknown causes at a Sandals resort, has left the country and is being treated at a hospital in Miami, the Royal Bahamas Police Force commissioner said Sunday.

The woman, whose identity has not been released, is in serious condition, Commissioner Paul Rolle said. She was initially airlifted to a hospital in Nassau, CNN reported.

Foul play is not suspected in the three deaths Friday, Bahamian Acting Prime Minister Chester Cooper said. The identities of the Americans who died will be released Monday after “official identification” is complete, Rolle told CNN, as authorities try to figure out why they died.

The three deaths at Sandals Emerald Bay resort on Great Exuma were also confirmed by Sandals spokeswoman Stacy Royal and the US State Department.

“We are closely monitoring local authorities’ investigation into the cause of death. We stand ready to provide all appropriate consular assistance,” the State Department said in a news release. “Out of respect for the privacy of the families, we have nothing further to add at this time.”

Resort staff alerted police shortly after 9 a.m. Friday that an unresponsive man had been found in a villa, police said. En route to the scene, police were told another man and woman were found unresponsive in another villa, the release said.

Police found in the first villa a “Caucasian male lying on the ground unresponsive” with no signs of trauma. A doctor pronounced him dead, police said. The woman who was hospitalized was found with him, Rolle said Saturday.

At the second villa, they found a second man “slumped against a wall in a bathroom unresponsive,” and the woman was “found in a bedroom on a bed,” the statement said.

“Both showed signs of convulsion,” the release said. Neither showed signs of trauma. They were also pronounced dead by a doctor.

The man and woman at the second villa had “complained of illness the previous evening” and gotten treatment at a local medical facility before returning to their accommodation, police said.

The woman who was hospitalized had been found in the first villa with the man who died, Rolle told CNN on Saturday.

Cooper on Friday asked the nation’s health and wellness minister to lead a delegation of health, environment and public works officials to the Exuma district. The Department of Environmental Health Services remained on the scene Monday, Rolle said.

“Nothing is more important to Sandals Resorts than the safety of our guests,” the resort said in a statement, adding it is actively working to “support both the investigation as well as the guests’ families in every way possible.”

CNN’s Hira Humayun, Jason Hanna, Rebekah Riess, Sarah Jorgensen and Susannah Cullinane contributed to this report.