Authorities on the southeastern Aegean island of Rhodes are investigating the death of two sisters in a hotel swimming pool the previous evening.
The two girls have been identified as French tourists who were holidaying on the island with their families. They were aged 16 and 19 years old.
The incident occurred in the late afternoon, after the hotel lifeguard had gone off duty.
Reports suggested that one may have drowned trying to save the other, though the sequence of events is unclear as there appear to have been no witnesses.
According to the Athens-Macedonian News Agency, a local prosecutor has ordered the arrest of the hotel's managers so they can face questioning.