There were signs of life signals, but rescuers needed confirmation in a rescue attempt for trapped workers after a gold mine blast in east China's Shandong Province, authorities said on Sunday.
As they drilled a channel at 1:56 pm on Sunday, rescuers knocked on the drilling pipe and got knocking sounds back in response.
The rescuers would deliver nutrient solutions and put life detectors and wired telephones into the mine as soon as possible, said Sun Shufu, an official with the emergency management department in Yantai City.
The blast took place at 2 pm on January 10 at a gold mine in Qixia under Yantai City. It happened about 240 meters away from the entrance. Twenty two workers were working more than 600 meters away from there.