The death toll from a mudslide that resulted from a collapsed mine waste reservoir earlier this week in northern China has climbed to 178, state media said on Friday. "Rescue work is still being carried out urgently," the official Xinhua news agency said, with rescuers have searched 90 percent of the area covered by the mud. Heavy rain triggered the disintegration of the holding pond at the iron mine in Shanxi province after it had been overfilled with waste ore, state media quoted an initial investigation as saying, according to a report of Reuters.