XIANGNING, China - Rescuers pumped water from a flooded mine in northern China where time is running out for 153 trapped workers as efforts stretched into a second day with no communication from those stuck deep underground.
Some 1,000 rescue workers were rotating on shifts to try to drain enough water to reach the trapped miners, but the rescue effort could take days. It was unclear if anyone was still alive in the shafts, some which extended one kilometre into the earth.
The accident could be one of the worst mining disasters in recent years if rescue efforts fail and would set back marked improvements in mining safety.
"Their situation until now is still unknown so that is making everyone very worried," said Liu Dezheng, a chief engineer with the work safety bureau in northern China's Shanxi province, where the mine is located.
The flood at the state-owned Wangjialing coal mine may have started Sunday afternoon when workers dug into a network of old, water-filled shafts. Such derelict tunnels are posing new risks to miners across China even as the country improves safety in its notoriously hazardous mines, where accidents kill thousands each year.
China's State Administration of Work Safety said 261 workers were inside the mine when it flooded, and 108 escaped or were rescued.
"We can't get in touch with the people down there," said miner Li Jianhong, 33, who was helping move pipes to suck water from the shaft. "If they haven't drowned yet, they might have suffocated from a lack of oxygen."
He was just about to head into the mine for his shift on Sunday when he heard that "something happened" underground. As he and his colleagues gathered for a meeting, they received a call from some of the trapped miners.
"We just received one phone call from them and after that there was no more contact. Those poor people," he said.
Liu warned any rescue was still days away and said the 1,000 rescuers were rotating on four-hour shifts to make sure they got enough rest in the days ahead.
"This is not something that can be achieved in one or two days," Liu said. "(Rescuers) must be prepared to work at least seven days and seven nights."
In the parking lot of the mine Tuesday morning, a team of men in orange suits, red helmets and black rubber boots pulled on backpacks with oxygen tanks and prepared to go into the mine.
Dozens of frustrated relatives, including women carrying small children, gathered near the mine office, demanding rescuers pick up the pace. A few amid the crowd of about 60 people shouted at police who were trying to keep them from rushing into the office, though the scene was generally peaceful.
Tang Yinfeng, a migrant worker from south China's Hunan province, said two of her younger brothers were trapped underground. "I want to bring oxygen tanks down," said Tang, 49. "I want to save them myself."
State television said the workers were trapped in nine different places in the mine, which was flooded with up to 140,000 cubic metres of water.
Authorities were not only worried about the flood. Gases from the abandoned shafts may have flowed into the mine, bringing new dangers such as explosions or poisoning.
Officials have yet to declare the cause of the accident, but experts said it was likely that workers broke into the old shafts or pits of derelict mines that had filled with water.
David Feickert, a coal mine safety adviser to the Chinese government, said hidden shafts are a common cause of mine floods. Shanxi would be particularly vulnerable, he said because "Shanxi is an area where they have very extensive mining, a lot of old mines."
Though China's mining industry is still the world's deadliest, it has dramatically improved its safety record in recent years.
Accidents killed 2,631 coal miners last year, fewer than half the 6,995 deaths in 2002, the most dangerous year on record, according to the State Administration of Coal Mine Safety. That means on average more than seven miners die every day, down from 19 in 2002.
Much of the safety improvement has come from shutting down smaller, labour-intensive operators or forcing them into mergers with better-funded state companies.
Major mine accidents in China in recent years include a coal mine flood in eastern Shandong province in August 2007 that left 172 miners dead and a mine blast in northeastern Liaoning province in February 2005 that killed 214 miners.
