BEIJING -- Rescuers heard tapping sounds Friday from the pipes in a flooded Chinese coal mine where 153 workers were trapped more than five days earlier, and another rescue team reportedly heard shouts, an official said.
The sounds at the Wangjialing mine in the northern province of Shanxi were the first signs of life since the mine was flooded Sunday afternoon, rescue official Zhao Chuan said.
Government officials say the flood was triggered when workers digging tunnels broke through into an old shaft filled with water. More than 1,500 rescuers have been working around the clock to pump water out of the mine.
Wen Changjin, an official from the news center set up at the site, said rescuers tapping on the pipes began to hear tapping responses from about 820 feet (250 meters) below ground at around 2 p.m.
Zhao told The Associated Press by telephone that he had heard from colleagues that another rescue team reported hearing people shouting underground as well but he could not immediately confirm that account. Wen said officials at the news center had not heard reports of shouting.
He said rescuers have started sending glucose and milk down the pipes to the spot where the tapping was heard.
Zhao was quoted by China Central Television as saying that an iron wire was found tied to a drill rod and rescuers think it may have been attached by one of the trapped miners.
Footage on the state broadcaster showed rescuers tapping on pipes with a wrench, and then cheering and jumping in joy when they heard a response.
The 153 workers were believed to be trapped on nine different platforms in the mine, which was flooded with up to 37 million gallons (140,000 cubic meters) of water, the equivalent of more than 55 Olympic swimming pools, state television has reported.
Some of the platforms were above the underground water level, a spokesman for the rescue headquarters, Liu Dezheng, told state media Wednesday.
"It is believed that some workers may have a chance of survival," Liu said. "We will go all out to save them."
David Creedy, a former mine consultant who now works in China as coal mine methane director for Sindicatum Carbon Capital, said if the mine's tunnels remain open with no cave-ins, rescuers should be able to reach the miners by pumping out the water or sending a diver through.
"Certainly for the current time, a week or so, there's a good chance" for their survival, he said, though factors also include how cold and wet the miners are, and how much air is available.
A preliminary investigation found that the Wangjialing mine's managers caused overcrowding in the shaft by assigning extra tunneling crews in a rush to finish the work, and ignored warning signs, the State Administration of Work Safety said.
"Water leaks were found numerous times on underground shafts," but the mine's managers "did not take the actions necessary to evacuate people," it said.
It could prove to be the deadliest mine accident in China since a coal mine flood in eastern Shandong province in August 2007 killed 172 miners.
China's coal mines are the world's deadliest, despite a multiyear government effort to reduce fatalities. Most accidents are blamed on failure to follow safety rules or lack of required ventilation, fire controls and equipment.
Accidents killed 2,631 coal miners in China last year, down from 6,995 deaths in 2002, the most dangerous year on record, according to the State Administration of Coal Mine Safety.
Also Friday, officials said the death toll from an explosion at another mine in central China had risen to 19 people, with 24 still trapped underground.
A gas leak caused Wednesday night's blast, according to a report on the Web site for Luoyang city in the central province of Henan.
In a third accident, a coal mine fire in the northwestern province of Shaanxi killed nine people Thursday evening, Xinhua said. Another 17 miners escaped. Xinhua did not say what caused the accident.