The huge gold mine in Indonesia's Papua shut down operations late last week, citing a campaign of violence and intimidation by employees against workers who did not join last year's strike.
In a press release a Freeport McMoRan spokesperson, Ramdani Sirait says some returning workers have engaged in acts of violence and intimidation against non-striking workers.
He says the company is working with union officials and government authorities to resolve the ongoing issues.
The statement did not detail the nature of the violence but three workers have been arrested and are being held in police custody.
Virgo Solossa, the head of the Mimika chapter of the All-Indonesian Workers Union told the Jakarta Post that employees stopped working because the company had failed to fulfill part of an agreement signed in late December.