Jakarta. Rescuers are racing to save seven workers trapped underground after a landslide struck Freeport Indonesia’s (PTFI) Grasberg Block Cave mine in Central Papua on Aug. 8, with efforts hampered by unstable mud and collapsed tunnels.

“I am deeply concerned and I believe Freeport has maximum systems and mechanisms in place,” State Owned Enterprises Minister Erick Thohir told reporters in Jakarta. “We pray for our brothers, but I don’t want to speculate on their condition as we do not yet know.”

Freeport’s Emergency Response Group has been working around the clock since the collapse late on Aug. 8, battling unstable mud that continues to push deeper into the tunnels. Despite deploying heavy equipment, drills, and drones, rescuers have yet to locate the seven miners.

Deputy Energy and Mineral Resources Minister Yuliot Tanjung said the workers were initially able to communicate with rescue teams via radio shortly after the incident. Based on those exchanges, Freeport estimated it could reach the site within 30 hours by digging two new tunnels. However, communication was later lost and the workers remain unaccounted for.

“The complex and winding underground conditions make it difficult,” Yuliot said. “The handy talkie used for communication is no longer functioning, which adds to the challenge.”

Freeport Indonesia President Director Tony Wenas said all available resources have been mobilized to free the trapped miners. “Our emergency teams are working tirelessly to open access to the estimated location of the workers, while trying to restore communication,” he said.

The company, a subsidiary of US-based Freeport-McMoRan and part of Indonesia’s state-owned mining holding MIND ID, is coordinating closely with inspectors from the Energy Ministry in the high-risk operation.

The Grasberg mine in Papua is one of the world’s largest gold and copper reserves.

Authorities have not yet confirmed whether the seven trapped miners are still alive.