The church says it filed the case after it was approached by mine workers for help.

The Southern African Bishops Conference said on Wednesday that lawyers filed papers with South Africa’s High Court on Tuesday.

“Very often ex-mine workers are no longer members of trade unions and, therefore, lack the means and capacity to seek legal recourse from large companies which are responsible for their lung diseases,” Archbishop of Cape Town Stephen Brislin said.

“It is thus incumbent on the church to give assistance where it can, … so that they can access compensation that is legally due to them.”

The miners are represented by Richard Spoors, a lawyer who has won compensation in similar cases before.

Filed on behalf of 17 former and current mine workers, the case targets mining giant BHP, its spin-off South32 and South Africa’s Seriti, Dasantha Pillay, a lawyer with Spoors’s firm, told the Agence France-Presse news agency.

It seeks recourse for all miners who worked for these companies since 1965 and contracted lung disease as well as dependents of workers who died from coal dust-induced illness.

The firms did not immediately reply to AFP’s request for comment.

The church said it initiated and facilitated the case after it was approached by mine workers for assistance.

Coal is a bedrock of South Africa’s economy, employing almost 100,000 people and accounting for 80 percent of electricity production. The industry is concentrated in the eastern region of Mpumalanga, which environmental campaigners Greenpeace said has some of the dirtiest air in the world.

The class action accuses the companies of failing to provide their workers with adequate training, equipment and a safe working environment despite knowing the risks to coal miners.