A swimming outing off the Bahamian island of Bimini ended in tragedy Friday when powerful currents swept a group away from shore, leaving two American visitors dead, according to the Royal Bahamas Police Force.

The victims, a 38-year-old man and a 40-year-old woman, were among swimmers who had entered waters beyond a posted warning about strong currents, police said.

A nearby ferry came to the group’s aid and rescued several people. However, the two Americans were unresponsive when rescuers reached them. Rescuers administered CPR before taking them to a local clinic, where medical staff continued attempts to revive them.

Both were pronounced dead shortly before 4 p.m., according to the police statement.

Investigators said they did not suspect foul play but were examining the circumstances surrounding the incident. Autopsies were planned to establish the precise causes of death.