The division between management and workers at the strike-hit Escondida copper mine in northern Chile has widened amid accusations of violence and unfulfilled promises.
In a statement over the weekend, the BHP Billiton-controlled company said around 300 masked individuals had marched Saturday from the union's strike camp into the mine site, threatening contractors, activating fire alarms and vandalizing installations.
Production at Escondida, the world's largest copper mine, has been halted after workers walked out on strike February 8.
The open pit mine produced around 1 million mt of copper last year in cathode and concentrates.
Striking workers also blocked the access road to the mine and roads inside the mine and electricity to the main access gate was also cut, requiring security staff to withdraw.
In response, the contractors' camp has now been evacuated, said Escondida's vice president for corporate affairs, Patricio Vilaplana.
"We categorically reject these actions which infringe the law and the company's value ... and the company will take the necessary legal actions to ensure the safety of all mine workers," Vilaplana said.
Union leaders have denied many of the accusations claiming that the march was peaceful.
BHP Billiton owns 57.5% of the Escondida mine, which it also operates. Rio Tinto owns 30% and a Japanese consortia owns the remainder.
