Efforts are underway to rescue survivors from one of South Africa’s deepest mines, where hundreds of illegal miners have been trapped underground for months.

A cage-like structure was sent down to the Buffelsfontein Gold Mine in a bid to bring out the survivors. Authorities believe over 100 miners have died from starvation or dehydration, AP reports.

Since Friday, 18 bodies and 26 survivors have been recovered from the mine. However, more than 500 miners are feared to still be trapped underground. While police are uncertain about the exact number, it is estimated that hundreds remain inside.

The mine, located near Stilfontein, southwest of Johannesburg, has been at the center of a standoff between miners, police, and local communities since November. The conflict began when authorities launched an operation to remove illegal miners. Some miners have reportedly been underground since July or August of the previous year.

Chinese gold mining endangers Congo's protected UN heritage site

Authorities insist the miners are refusing to leave, but rights organizations have contested this claim. They have criticized police for cutting off food and water supplies to force the miners out. Activists argue that many miners are unable to climb out because the shaft is too steep, and the ropes and pulley systems they used to enter have been removed.

Illegal mining is widespread in South Africa, especially in abandoned, gold-rich mines. Miners often stay underground for months, relying on supplies sent from the surface by others. Some miners have escaped since November, but many fear arrest if they emerge.

Rights groups say the miners’ only escape route is a dangerous journey to another shaft, a trek that can take days. The mine, 2.5 kilometers deep, is a maze of tunnels and multiple shafts. In December, a mining advocacy group took authorities to court to ensure food, water, and medicine were delivered to the trapped miners.

Two cellphone videos released by the group show emaciated miners and numerous dead bodies. South African authorities continue to face scrutiny for their response to the crisis.