The Department of Mineral Resources and Energy (DMRE) has sent its condolences to the families of four mine workers who died following the collapse of a surface waste rock conveyor.

The incident occurred on Thursday afternoon at the Sibanye Stillwater Burnstone Gold Mine in Mpumalanga.

"It was reported that on Thursday...an incident occurred at the mine during the installation of a pulley for the waist rock conveyor belt. The incident involved the use of a 140-ton crane to lift the pulley from the ground and place it in position. As the pulley was being aligned, the conveyor belt structure collapsed and injured multiple employees, four of whom have since succumbed to their injuries.

"We would like to extend our heartfelt condolences to the families and colleagues of the workers who have sadly lost their lives. One life lost is one too many. No one deserves to lose their life in the line of duty. We wish the injured workers speedy recovery," the department said.

The DMRE said an investigation is underway to determine the cause of the incident.

"The Department's Mine Health and Safety Inspectorate, which visited the mine yesterday, has commenced a full investigation in terms of the Mine Health and Safety Act, to determine the cause of the incident that took place.

"The health and safety of mineworkers remain a priority for government. Employers are urged to be vigilant on the management of health and safety of mine workers. We must all work tirelessly work towards achieving Zero Harm in South African mines, thereby ensuring that each employee returns home unharmed every day," the DMRE said.

The mine has also conveyed its condolences with an internal investigation underway as well.