According to Mining News Pro -Workers of Chile’s Escondida mine, the world’s largest copper mine, decided to go on strike on Nov. 21 and 23 due to labor demands, their union said on Tuesday.

Members of the union, Sindicato 1, had threatened to strike in early September as they expressed concerns over security in the mine, which led to inspections by government authorities.

Union members will stop operations in all their shifts during the strike but will provide minimum services, Sindicato 1, which represents more than 2,000 workers, said in a statement.

Infractions by Minera Escondida, which manages the mine and is controlled by BHP Group, have continued, with the company failing to adopt preventive measures despite security incidents, like fires, the union said in the statement.

The union said it notified the company of the strike.

Minera Escondida has denied the union’s accusations.

The mining company and the union have faced off before, including in 2017, when workers went on strike for more than 40 days.