The death toll from a boat found south of Crete rose to 14 on Monday after one of the people rescued from the vessel died at a health centre, Greek authorities said.

The coast guard recovered 13 bodies from the boat, which was found sailing south of the island early on Monday. Eighteen other people were rescued from the same vessel; one later died, bringing the confirmed death toll to 14.

Authorities had not immediately identified the people on board or confirmed their nationalities. The cause of death was also not immediately known, the Associated Press reported.

The confirmed figures concern this vessel only. Separate rescue operations in the region should not be conflated with the incident, and no departure point or intended destination for the boat has been confirmed in the information available so far.

The circumstances remain under investigation. Further updates from Greek authorities may clarify how long the boat had been at sea, where it began its journey and what happened before it was found.