South Korea rescue officials on Sunday pulled a third body from the rubble after the collapse of a large structure at a power station, according to media reports.

The reports also claimed that as many as four more people remained buried in the rubble, with the authorities unable to locate two of them.

A 60-meter tower at Korea East-West Power’s Ulsan Power Plant headquarters, in Ulsan, reportedly collapsed during demolition work at the decommissioned heating facility on Thursday, November 6.

Footage from the scene in Ulsan on South Korea’s southeastern coast showed the structure mangled and toppled over, surrounded by similar structures.

Rescuers have deployed heat sensors, remote scopes and search dogs to assist the rescue operation and locate the other trapped workers, though their efforts have been hampered by the risk of a further collapse of the structure.

South Korean Prime Minister Kim Min-seok ordered all ministries to “mobilise all available personnel and equipment, placing top priority on rescuing those trapped.”

Residents were also being evacuated from the area, the Prime Minister’s Office added.

The workers were reportedly dismantling parts of the massive steel structure to prepare for demolition when it suddenly collapsed.