(NewsNation) — An American woman has been reported missing after she failed to return to a cruise ship in the Caribbean.

The Police Force of St. Martin said Ann Evans, 55, was a guest aboard the cruise ship Rotterdam, which was docked in Port St. Martin on Nov. 20. Evans departed the ship for an organized island tour. During the tour, she disembarked the bus in Marigot, French Saint Martin, but did not return to the bus or to the ship.

“Efforts to locate Ms. Evans are ongoing, and law enforcement authorities on both the Dutch and French sides of the island have been alerted,” the Government of Sint Maarten wrote in a missing persons alert.

No information has been released on whether Evans was traveling with anyone or boarded the cruise alone.

Per its website, Rotterdam is the newest ship in Holland America Line. The ship can house upwards of 2,600 passengers at double occupancy or up to 4,173 guests when its staterooms are fully booked.

KPSM and the French Gendarmerie are urging anyone with information about Evans’ whereabouts to come forward.