Police in Indonesia say four people are now known to have died after a tunnel collapsed at a giant gold and copper mine on Tuesday.
Ten men have been rescued, but dozens more are said to be trapped underground since early Tuesday at the Grasberg gold and copper mine in the mountains in Papua, an eastern province.
Mine owner Freeport-McMoRan, an American company, said the rescue operation is difficult and will take some time.
The company previously said 37 people had been trapped when the tunnel collapsed as workers took part in a training exercise, but on Wednesday revised that figure up to 39.