May 27 (UPI) — Five of seven men trapped in a cave in a remote area of Laos for more than a week were found alive on Wednesday following an international rescue operation involving more than 100 volunteer personnel.

The Laotian group Rescue Volunteer for People said the five, all men, were safe and well and that the search for the two remaining missing people would continue.

However, rescuers warned that the five people, who became trapped a quarter of a mile down by landslides and flooding after entering the cave system on May 20, remain stuck and have yet to be brought to the surface.

“The extraction is still ahead and it ain’t going to be easy,” said Finnish cave rescue diver Mikko Paasi, one of several specialists and organizations involved who also took part in the Tham Luang cave rescue in 2018 when a Thai teen soccer team and their coach were trapped underground for more than two weeks.

“The task so far has been far from easy and everybody involved has done amazing work,” he said.

Paasi said he and another diver were preparing to make a second dive to bring supplies to the group, who have been without food or proper rest for days, to build up their strength in readiness to make the trip out from the cave.

Kengkard Bongkawong of the Thailand-based Metta Tham Kalasin Command and Control Center, one of the groups coordinating the operation in the central province of Xaysomboun, said rescuers were being challenged by a part-submerged 1,115-foot-long tunnel that narrows to as little as 23 inches in places.

The rescue teams spent Monday and Tuesday pumping out as much water as possible and placing fixed ropes inside for rescuers to follow after being forced back by rising water from torrential rains Sunday night.

The group of local men was on a hunting and gold prospecting mission when they became trapped by rising water in the cave after heavy rain that also triggered landslides that sealed off the entrance.

Two divers, both former Thai Navy SEALs, were killed in the Tham Luang rescue in northern Thailand, which snowballed into a huge international operation involving 10,000 specialists from cave rescue and medical experts to Elon Musk, who had his engineers develop a mini rescue submersible.