One worker was killed after a new tunnel collapse on Friday at Freeport McMoRan Copper and Gold Inc's Indonesian mine, a union official said, calling on miners to stop work at the world's second-biggest copper mine.
Company officials could not be immediately reached, but this would be the second deadly collapse at the remote Papua complex in just over two weeks after 28 people were killed in one of Indonesia's worst mining disasters.
Papua-based union official Virgo Solossa said by telephone the worker had been killed after "a tunnel collapse at an underground drop point out of Freeport production area".
A person had been buried after a landslide in Freeport's DOZ underground mine, said another source who works at the Papua mine, who asked not to be named.
Freeport suspended operations at the Grasberg complex in eastern Indonesia on May 15, a day after a training area in a tunnel, away from the site of its main operations, caved in on 38 workers.
Freeport said on Wednesday it had resumed some operations at the mine, which also holds the world's largest gold reserves. The union had reiterated that work would not resume until all investigations into the May 14 accident were complete.
"This latest accident shows how Freeport management is arrogant after they have forced themselves and the workers to go back to work and re-start production activity," Solossa said.
"That's why the union calls all workers to stop working at all Freeport mining area."
The union represents about 18,000 of the mine's 24,000 workers.
Open-pit mining at Grasberg normally produces around 140,000 tonnes of copper ore a day, while underground operations yield 80,000 tonnes.
The problems at the mine have helped underpin copper prices, although a prolonged shutdown would be necessary to hit world supplies, which are still seen in a small surplus this year.
Freeport has been drawing on stocks to keep up overseas shipments during the production shutdown. Industry sources say large mining operations typically have three to four weeks of ore stockpiled at port, and around three days on site.
There was no immediate impact on copper prices on Friday with benchmark three-month copper on the London Metal Exchange trading at $7,321.25 a tonne, slightly higher than where it was trading after the mine closure.