New Zealand mine blast inquiry 'will leave no stone unturned'

Prime minister warns that it could take months to recover bodies of workers entombed in Pike River colliery after New Zealand's worst mining disaster for almost a century.

New Zealand's prime minister, John Key, said today that "no stone would be left unturned" to find why 29 men perished in a mine explosion that plunged the nation into mourning.

He warned that it could take months to recover the bodies of workers entombed in the Pike River colliery after New Zealand's worst mining disaster for almost a century and said grieving relatives were right to question why it happened.

As flags across the country flew at half-mast, Mr Key told the stricken families that all New Zealanders were "deeply sorry" for their loss and he was determined to establish why safety standards failed their loved ones.

"This is an inquiry that will leave no stone unturned to ensure that they get their answers as to why their men are not coming home," he told reporters.

The prime minister travelled to Greymouth, on the South Island, to comfort the bereaved, whose fading hopes after an explosion last Friday were snuffed out by an even bigger blast yesterday.

"The nation is grieving and mourning alongside them," he said.

Mr Key said after a sombre meeting with the families he detected resignation rather than the anger seen a day before, when relatives shouted at police and collapsed in anguish after being told their loved ones were dead.

Earlier, he acknowledged the families were desperate for the miners' bodies to be removed from the pit so they could be given proper funerals.

However, a lethal cocktail of volatile gases remained in the mine and Mr Key said this would delay recovery attempts.

Previous international experience had shown the operation could take "quite some months", he said.

As messages of condolence poured in from around the world, Key praised the rescue efforts, which some relatives of the miners have criticised after the gas threat stopped emergency workers from going underground.

The Pike River Coal board is to meet tomorrow to discuss the company's options, and its chief executive, Peter Whittall, said he favoured getting the mine going again.

"It's not like the mine was a big scary place that was waiting to kill them," he told reporters. "The mine was where we worked, it was where we went to every day, we understood it."

Pike River said it would cooperate with any government inquiry and was holding its own investigation into the disaster at the mine, which sent its first shipment of hard coking coal for steelmaking to India only this year.

The tight-knit community on the South Island's west coast was scarred but accepted the risks that accompanied the mining industry upon whch it was built, the local mayor said.

"Inherently coal mining is dangerous, we live with, that's all part of the way we live here on the west coast," said Tony Kokshoorn, the mayor of Grey District.

The head of the rescue effort stood by his decision not to send emergency crews after the victims, who included 24 New Zealanders, two Australians, two Britons and a South African.

The second blast that tore through the colliery had brought home to rescuers what would have happened had they been in the mine shaft at the time, police superintendent Gary Knowles said.

"When you look at men who are hard men, who are crying, you are hit with the reality they could have been down there," he said.

Britain's Queen Elizabeth II, who is also the head of state of New Zealand, and the US secretary of state, Hillary Clinton, were among the dignitaries who expressed condolences over the tragedy.

Australia's prime minister, Julia Gillard, said hopes for a repeat of a dramatic rescue in her own country at Tasmania's Beaconsfield mine in 2006 and last month's retrieval of 33 Chilean miners had been dashed.

She said: "After Beaconsfield then Chile this year I suppose in some part of our minds we were always hoping, always thinking that there's going to be a happy ending. Unfortunately, and tragically, there wasn't."