BANGKOK - A desperate search is underway in central Laos for seven villagers trapped inside a flooded cave for the past seven days. Rescuers face treacherous terrain and relentless heavy rain as they battle to reach the group, whose condition remains unknown.

The villagers entered the cave in Xaisomboun province on May 19. Flash flooding triggered by heavy rain blocked the exit. Rescue teams from Thailand, including experts who helped in the 2018 Tham Luang cave rescue, arrived over the weekend to assist.

Divers have navigated roughly 100 meters into the flooded, narrow cave. They believe the victims may be trapped about 30 meters further. Rescuers are now pumping water out and exploring air shafts above the cave to find alternative access points.

The cave is located in a remote, mountainous area roughly 120 kilometers north of Vientiane. Reaching the entrance requires a steep 4-kilometer hike. Inside, rescuers must crawl through muddy passageways and narrow tunnels.

While there is no official confirmation on why the villagers entered the cave, rescuers say they were likely looking for gold deposits. Average per capita income in Laos is low, and mining is a common activity in rural areas.

The Laos Foreign Ministry said Tuesday it has no official information to share. The nation is a one-party communist state with tight control over information.

Cave rescues are inherently risky. The 2018 Tham Luang rescue in Thailand killed a former Thai navy SEAL. Earlier this month, five Italian divers died in a cave diving accident in the Maldives, along with a Maldivian military diver.

Health risks for those trapped include hypothermia, dehydration, declining oxygen levels, carbon dioxide buildup, and extreme sensitivity to light after days in darkness.