Rescue officials say falling rocks are hampering their progress in reaching 23 trapped workers at a gold and copper mine in Indonesia, and chances of finding any more survivors are declining. The head of the emergency response team at PT Freeport Indonesia, Nurhadi Sabirin, said Saturday that rescuers have not detected any signs of life in several days. A tunnel collapsed last Tuesday when 38 workers were undergoing training inside an underground classroom. Ten miners were rescued and five bodies were recovered. Sabirin said "as more time passes, the possibility of there being any survivors becomes less likely." More than 20,000 workers are employed at the mine in Papua province owned by Phoenix, Arizona-based Freeport-McMoRan Copper & Gold Inc, according to a report of the Associated Press.