Efforts to rescue 29 men trapped in a New Zealand coal mine have stalled for a third day.
There has been no contact with the miners since an explosion ripped through the Pike River colliery on the rugged west coast of New Zealand's South Island on Friday, with authorities saying gas levels meant that it was still too dangerous to enter.
Anger and frustration has been growing over the stalled rescue, with New Zealand authorities being questioned over the preparedness of a mining industry thought to be among the most safety-conscious in the world to cope with such a disaster.
"These are very testing times and families are feeling high levels of fear, anxiety and frustration," Prime Minister John Key told a news conference today.
A robot provided by the New Zealand Defence Force is being modified to allow it to safely enter the mine where high levels of flammable methane gas are still being recorded, to see if the main shaft was blocked in the explosion.
Special equipment to measure and analyse gas levels has also been flown in from Australia, and seismic equipment was also to be used to search for any signs of life.
The robot is expected to enter the mine this afternoon, after it has been modified to ensure it does not generate sparks which could ignite any methane within the shaft.
"Everybody's frustrated, everybody's upset, everyone's hurting," said Laurie Drew, whose 21-year-old son, Zen, is among the trapped men. But he added: "We've got faith that they're going to come out...."
Drilling of a 15cm diameter shaft on a steep hillside above the mine had been underway since last night, and is now believed to have reached two-thirds of the estimated 162m depth to the main mine shaft, which is dug horizontally into the side of a mountain range.
It is expected to break through to the mine shaft this afternoon, and authorities hope to send down a camera and laser imaging equipment to look for any sign of the men, and a tube to constantly monitor the air quality.
Officials refused to speculate whether the men were still alive after being trapped with no food and, it is believed, limited water.
"The situation remains grave and every effort is being made to carry out a rescue," police commander Gary Knowles said. "We remain optimistic that this is a search and recovery operation."
The disaster follows the ordeal of 33 Chilean miners trapped in an underground chamber for two months before their dramatic rescue last month, when they were hoisted one by one to safety through a hole drilled 700m through rock.
An explosion of naturally occurring methane gas is thought to have caused the coal mine explosion. High levels of gas have been detected near mine ventilation shafts. Authorities say it is possible that the miners have survived the blast and are sheltering in an area where the air is cleaner.
Tests on the air quality are being conducted every 30 minutes at the mine's shafts, and this will continue around the clock until they show levels falling to where it is safe to enter.
The trapped men range in age from 17 to 62 and include two Britons, two Australians and a South African. Two men escaped from the mine after the blast with moderate injuries.
With sunny skies for the first time in days, families were due to be taken back to mine, located in forest-clad mountains.
The isolated mine has been dug about 2.3km into a mountain range, with the trapped men believed to be most of the way inside. There are ventilation shafts climbing vertically at least 100m to the surface to provide fresh air, and a compressed air line is still being pumped in.
Reuters