BHP, Rio face strike in Chile

Staff walk off the job at Escondida, the world's largest copper mine.

Employees at a Chile copper mine owned by BHP Billiton (BHP) and Rio Tinto (RIO) have gone on strike for improved working conditions and pay, ABC News reports.

According to the publication, around 2,500 workers downed tools for a planned 24-hour protest, which their union has not ruled out extending.

The action began after managers refused to pay an annual bonus not covered in workers' contracts, while staff also want a system to track overtime and the removal of surveillance cameras from mining trucks, according to the ABC.

BHP Billiton owns 57.5% of Escondida, while Rio Tinto owns 30%, and the miners recently committed over $1 billion each to sustain operations at the project through constructing a new desalination facility.