Rescuers in Laos were scrambling on Tuesday to reach seven people who have been trapped in a flooded cave since last week after entering it in search of gold, authorities said.

The group entered the cave on Wednesday, local authorities said, and got stuck when heavy rain caused flooding that swept gravel and dirt into the entry passage, blocking it.

They were trapped in a chamber more than 100 yards from the cave entrance, according to a graphic shared by Kengkard Bongkawong, the president of Metta Tham Rescue, a Thai organization invited by the Lao government to join the rescue effort. It was not clear what the group’s condition was.

Divers spent nearly three hours inside the cave on Monday afternoon, according to Mr. Kengkard. Photos posted by rescuers on social media showed a narrow cave filled with water, leaving little room for the divers to breathe or store oxygen tanks.

For the rescuers, “It’s like crawling through a drinking straw,” Mr. Kengkard said in a social media post on Monday. “If it rains, the water level will rise quickly. Finding a suitable place to store tanks is impossible because even just squeezing through is difficult.”

Metta Tham Rescue was involved in the successful effort to free the youth soccer team that was trapped in a cave in Thailand for 18 days in 2018. The Lao government permitted three other divers from Thailand and Finland who were involved in the 2018 rescue to enter the country on Sunday.

Past cave rescues have been complicated by flooded passages, limited oxygen supplies for divers and the race to reach people before they run out of air.

Early Tuesday, Mr. Kengkard said in a social media post that the rescuers were trying to enter the cave from above by rappelling through shafts in a mountain.

The cave is part of an extensive underground network in Xaysomboun, a mountainous province about 70 miles northeast of Vientiane, the Lao capital. The landlocked nation’s caves are popular for trekking and tubing among tourists, as well as local villagers sifting for gold and other valuable minerals. Though Laos’s national poverty rate has steadily declined, it has stagnated in rural areas, according to the Lao Statistics Bureau.

People regularly visited the cave looking for gold, despite repeated warnings from the authorities not to enter it, Buonkham Luanglath, the head of Laos Rescue Volunteer for People, a group of civilian rescuers, told The Associated Press on Monday.