**Rescuers trying to reach miners trapped in the Wangjialing mine in China’s Shanxi province are facing of a build-up of toxic gas, officials have warned.**Seven miners are confirmed to have died when the pit flooded and work is continuing to find the missing 31.
Search teams have managed to bring 115 of the 153 trapped miners out alive.
The rescue operation, underway for more than a week, has been described by officials as miraculous, with miners surviving by eating tree bark.
But cramped conditions and the risk of a gas explosion are raising the risks now facing the rescuers.
The tight mine shaft is impeding efforts to operate pumps to extract the water which is flooding the mine.
Still hopeful
The authorities have said there is still hope for those trapped, even though they are believed to be in the deepest part of the mine.
One section is thought to be cut off by a submerged stretch 700 metres (yards) long and the other by a 300-metre span, China’s official Xinhua news agency reported.
“We are doubling our efforts so we do not waste time,” Liu Dezheng, vice-director of the Shanxi work safety administration, told reporters at a news briefing.
“Now we’re racing against time and putting efforts in full swing to concentrate on these two areas,” Mr Liu said, in a reference to two work platforms where the remaining 31 miners are thought to be.
"There are 31 workers there, holding on, waiting for us to rescue them - we must face the work ahead with this in mind.
“It’s only after we’ve pumped water out and cleared a way through that we can go in. If we can’t go in, we can’t rescue them,” he said.
But he said there had been no contact with the missing miners so far.
Journalists and relatives of the miners say they have not yet been allowed to visit victims of the disaster in nearby hospitals, and journalists have been prevented from gaining access to the relatives in hotels.
The miners had been trapped in the flooded pit since 28 March.
Survivors have spoken of picking sawdust and cardboard out of the filthy floodwaters to eat and of strapping themselves to shaft walls with their belts to escape the water.
Hospital workers said the survivors were suffering from cold, severe dehydration and skin infections from long immersion in water.
A total of 153 people were said to have been trapped underground, but families say this is an underestimate as many more were working in the mine at the time.This article is from the BBC News website. © British Broadcasting Corporation, The BBC is not responsible for the content of external internet sites.