Rio suspended mining and smelting and declared force majeure on customer contracts, citing an escalation in security concerns, a month after RBM general manager of operational services Nico Swart was shot dead on his way to work.

"Continued acts of lawlessness including blockages of roads, burning of equipment and intimidation of staff at mining operations are not only unacceptable and damaging to the country's reputation as an investment destination, but also impact the lives and livelihoods of mining employees, their families and surrounding communities," the council said.

"The Minerals Council calls on government to act swiftly to urgently restore law and order in the area."

Trade union UASA had called on the government and police in mid-June to help restore order to prevent Rio from following through on a threat to close down the operation, which employed about 5,000 people.

Mineral resources and energy minister Gwede Mantashe had met with RBM executives, local authorities and police in early June, to convey his condolences over Swart's assassination and invite the police to "help us deal with crime in mining".

Unions have recently expressed concerns including "a deadly and ongoing dispute that included a local traditional leadership squabble", locals demanding employment at the mine, relocation concerns and "ambiguous" social and labour plans.

Rio had curtailed RBM in December 2019 due to an escalation in violence and indefinitely suspended the US$463 million Zulti South development.

The minerals council said the murder of Swart and others was "a tragedy that will forever tarnish our country's reputation".

South Africa was rated high risk in terms of hard risk in the Mining Journal Intelligence World Risk Report 2020.