SANTIAGO – Chilean copper miners' unions called on Sunday for a re-evaluation of the operational continuity plans of the country's biggest miners during what they said was an "alarming" increase in coronavirus cases among workers.

In a statement signed by the union leadership of State-owned Codelco, the Mines Federation - which groups the majority of workers for Chile's major copper mines - rejected the "business as usual" discourse advanced by miners and the mines minister, Baldo Prokurica.

"The increase in cases is alarming and demonstrates that the preventive measures implemented with health and safety protocols aimed at self-care are not working and makes it evident that contrary to what the union believed, security and isolation measures have not immunized workers from contagion," the statement added.

The statement comes just days after unionized workers at Codelco, the world’s largest copper miner, said they were weighing walking off the job at some sites in order to implement a self-imposed quarantine after one of their members died from Covid-19.

So far, large copper companies including Codelco, BHP Group and Antofagasta have maintained production levels, bolstering Chile's sinking economy. But they have been hit by a drop in prices led by a reduction in demand from China, where the coronavirus outbreak started.

The Mines Federation argued that the metal market "is on the rise and with the revival of the Chinese market does not presage the financial debacle that some mining companies have wanted to sustain to endorse hasty measures such as the dismissal of workers alluding to the scope of the coronavirus."

It also called on authorities to order mining companies to be more transparent about confirmed coronavirus cases among their workers, and dismissed an audit ordered by Prokurica of mine operations amid the pandemic as "late and reactionary."

Chile has more than 170 000 cases and 3 300 deaths from Covid-19, the respiratory disease caused by the novel coronavirus, one of the highest rates of infection in the world per 100 000 inhabitants.

Neither Codelco, BHP nor Antofagasta immediately responded to a Reuters request for comment.