Divers have entered a flooded kilometres-long Slovenian cave to try to evacuate five people trapped deep inside for days as water levels begin to recede.

The head of Slovenia’s Cave Search and Rescue Unit said the first section of the 8.2-kilometre cave is passable for now.

“The divers are getting inside and we hope they will come out with evacuees in the course of the day, by evening at the latest,” Maks Merela said on Monday.

The group of five, a family of three adults and two tourist guides, had taken shelter on Saturday in a safe place in the Krizna Jama cave in south-western Slovenia, which can only be visited by boat.

Divers managed to reach them on Saturday and Sunday and bring them food, water, medicines and a heated tent, but the high water level made their evacuation impossible as they were more than two kilometres from the entrance to the cave.

“They are in a super psycho-physical condition, in a dry place. They have a heated tent and all supplies they need,” Merela said.

“They are only waiting to get out.”

He said that all exits will be passable when the water subsides, and that evacuees will be given diving suits if there is a need for them to swim out of the cave.

Merela said that this was the first time people have been trapped in Krizna Jama, a chain of underground lakes with emerald green water, the fourth largest known cave ecosystem in the world in terms of biodiversity.