Toxic gas has hampered the search for 141 trapped coal miners following an explosion in central China. With at least 25 people already confirmed dead, an official said the of survival of the trapped miners were "extremely slight."
High levels of carbon monoxide kept rescuers from reaching the site of Sunday's disaster in Shaanxi province, the official Xinhua News Agency said.
An official at the Shaanxi coal mine safety bureau said hope was fading fast for the trapped miners.
"The rescue effort has been extremely difficult due to large concentrations of carbon monoxide," said the official, who would give only his last name, Chen. "From my own experience the odds that the 141 still underground remain alive are extremely slight."
Some 127 workers managed to escape the state-owned mine, Xinhua said, citing the State Bureau of Production Safety. Some 45 were hospitalized, 11 with serious injuries.
The blast rocked Chenjiashan coal mine at 7:20 a.m. on Sunday, when 293 workers were underground, Xinhua said. The explosion was centered around coal pits five miles from the mine entrance.
Most of the miners who escaped were working close to the entrance, Xinhua said, and many suffered from carbon monoxide poisoning. High levels of carbon monoxide was preventing rescuers from reaching parts of the tunnels.
Witnesses said they saw "huge amounts of thick smoke pouring from the mine's ventilation vents," hampering rescue efforts, according to the Web site of the Communist Party's People's Daily newspaper.
Staff at Chenjiashan said communications with the trapped miners were cut off, the site said.
On its evening newscast, state television showed ambulances rushing to the scene as huge crowds of people gathered outside the mine's main gate.
President Hu Jintao urged rescuers to employ "all effective measures" to save the trapped workers, China Central Television said.
Premier Wen Jiabao, who arrived at the ASEAN summit in Laos on Sunday, said he was "extremely upset" over the accident.
He said the cause of the explosion would be thoroughly investigated and the government would continue to push for safer working conditions in the mines.
According to Xinhua, Chenjiashan is capable of producing 1.3 million tons of coal a year.
China's mines are the world's most dangerous, with thousands of deaths reported every year due to explosions, fires, cave-ins and flooding often blamed on lax safety rules and lack of required equipment.
The government has vowed to improve conditions and frequently orders mass shutdowns and safety checks after a fatal mine accident.
But despite the crackdown, accidents still happen on a near daily basis. Chinese officials have suggested that a countrywide energy shortage may be pressuring the mining industry to raise coal production.
The worst mining accident in four years occurred last month, when a massive explosion in the Daping Mine in central Henan province left 148 people dead.
It was sparked after mine operators failed to realize that extending the mine's shaft would greatly increase its gas level.
Also Sunday, 16 officials in the northern Hebei province were charged with helping to cover up a massive coal mine explosion June 3 that killed 14 miners and injured 23 others, Xinhua said.
It said the mine owner "collaborated with some local officials" to give a false death toll of one to investigators from the central government. The owner was worried that if the real figure was revealed, authorities would shut down his mine and he would lose more money, Xinhua said.
The officials' misconduct included failing to search passages for more trapped miners and secretly cremating five bodies.
AP