Sept 9 (Reuters) - Freeport-McMoRan ( FCX ) said on

Tuesday it temporarily halted mining in Indonesia's Grasberg

minerals district after a large flow of wet material blocked

access to parts of its underground mine, restricting evacuation

routes for seven workers.

The incident occurred late on Monday at one of five

production blocks in the Grasberg Block Cave underground mine in

Central Papua, the company said.

The location of the seven workers is known and they are

believed to be safe, Freeport said, adding that rescue crews are

working to clear the area for a safe and swift evacuation.

Freeport operates Grasberg, one of the world's largest gold

and copper mines, and had been building a smelter in Indonesia.

The smelter was damaged by a fire last year and was shut down.