Toxic gas levels remained too high yesterday to start a rescue of 29 men trapped in a New Zealand coal mine for nearly three days as drilling continued on a new shaft to test air quality.

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 afternoon, with authorities saying the gas level made it too dangerous to enter the mine.

An explosion of naturally occurring methane gas is thought to have caused the explosion. High levels of gas have been detected near mine ventilation shafts.

Drilling of the new six- inch shaft on a steep hillside above the mine started last night and went through the night. It was reported to be about halfway down the estimated depth to reach an area of the tunnel closer to where the trapped miners might be.

Authorities have said that it is possible that the miners have survived the blast and are in an area where the air is cleaner.

Tests on the air quality are being conducted every 30 minutes at the mine’s shafts, but the toxic gas levels have been fluctuating. They needed to be falling to allow rescue teams to go in.

Thirty rescuers, including Australian experts, are ready to go, but it’s been estimated that it would take them around two hours to walk over the uneven ground and through dark, smoke-filled tunnels.

Victims’ families waiting

GREYMOUTH, New Zealand – Grim-faced family and friends of the missing miners were
taken to the mine site and spent around an hour watching the rescue preparations.

Tests indicated the presence of a heat source which is generating gas, perhaps a fire or coal smoldering, said the Pike River mine’s chief executive, Peter Whittall.

“The increased gas levels are making it difficult,” he said, adding that a smoky vapor was coming out of the mine entrance.

District police commander Gary Knowles denied suggestions that they did not expect to find anyone alive.