Five people have been trapped in a cave in Slovenia since Saturday afternoon after heavy rain caused water levels to rise, authorities said.
The group – a Slovenian family of three adults and two guides – can’t be rescued until water levels in the Krizna jama cave have dropped, officials said.
The tour party is more than a mile (2km) inside the five-mile (8km) cave system, which sits around 36 miles (58km) south of the capital, Ljubljana, and can only be visited by boat.
All five people are well, said Igor Benko, the head of Slovenia’s Speleological Association.
They were sheltered in a safe place after food, water and a heated tent were delivered to them by rescuers who managed to reach the group on Saturday evening.
The rescuers moved them to a safe spot designed for such emergencies, officials said.
But a new team of divers is needed to get them out as they are more than one mile (2km) away from the entrance to the cave.
That operation is likely to take three to four hours, officials said, adding that the final rescue will depend on when the water levels fall.
It could be as soon as Sunday night but might also take a couple of days.
The group entered early on Saturday for a tour of the cave system with its chain of underground lakes.
Visitors are allowed in only as part of guided tours.
At least 35 cave rescuers and eight divers from all over Slovenia are involved in the rescue operation, along with 11 firefighters and members of the civil protection force, authorities said.
Krizna jama, a chain of 22 underground lakes with emerald green water, is the fourth largest known cave ecosystem in the world in terms of biodiversity, the attraction’s website said.
The boys, then aged 11-16, and their 25-year-old coach, were trapped for 18 days before they were rescued following an international effort involving around 10,000 people.