The desperate search for seven villagers in Laos prospecting for gold who became trapped deep inside a flooded cave entered a sixth day on Monday, with the incident highlighting how surging prices have sparked a rush for the precious metal despite risks in unstable hillside mines.

Thai cave rescue teams have joined the mission at the cave in central Xaysomboun province, posting harrowing images on social media of the conditions, which include crawling through a flooded, narrow tunnel leading to a mountainside.

The trapped group is believed to have entered last week. Three members of the group were found dead earlier after a landslip caused by heavy rains struck the cave.

The remaining seven are believed to have retreated further inside, with rescuers posting images online showing the treacherous conditions required to reach them, including navigating an impossibly narrow flooded channel.

It is unclear if any contact has been established with the group. They are likely hundreds of metres inside the mountain, according to the Mettadham foundation, also known as the Society of Kindness, a Thai NGO that carries out humanitarian rescue work.

The main challenge is entering through the “extremely narrow’’ flooded tunnel, where the room to breathe above the muddy water was only about “60cm [23 inches] in height”, the foundation said in a social media post on Monday.