SANTIAGO, Chile (AP) -- Chilean workers are staging a strike at the world's biggest copper mine.
The strike at the Escondida mine began Wednesday morning over demands for an annual bonus payment and improved working conditions.
Union leader Marcelo Tapia tells The Associated Press that the mine's 4,800 striking workers walked off the job for 24 hours, but they could extend the strike indefinitely if their demands are not met.
Chile is the world's top copper producing country. Escondida, which is located in the Atacama desert, produced 1.1 million metric tons of copper last year.
The mine is majority owned by Australian mining company BHP Billiton Ltd. Officials at BHP Billiton could not immediately be reached for comment.
Escondida's union staged a two-week work stoppage in 2011 that severely hit production.