A pit disaster that claimed 29 lives threatens New Zealand's entire underground coal industry, Prime Minister John Key warned Sunday, as another explosion rocked the gas-choked colliery.
The latest blast ripped through the Pike River pit just before 2:00pm (0100 GMT), underscoring the dangers inherent in underground coal mining, which has boomed in New Zealand in recent years on surging demand from Asia.
Speaking before the explosion, the fourth at Pike River since an initial November 19 blast trapped 29 miners, Key said the industry's future was in the balance while the risk of similar tragedies remained.
Announcing he wanted a powerful Royal Commission to investigate the disaster, Key told TVNZ: "In the end, the future of Pike River and actually underground coal mining in New Zealand rests on this.
"We can't put people into mines that are dangerous."
Police said there were no injuries in the latest explosion at the mine, which remains flooded with methane preventing the recovery of entombed bodies.
New Zealand has five underground coal mines, according to government resource body Crown Minerals, producing about 20 percent of the country's output. Key estimated some 450 people were directly involved in the industry.
However, the wealth generated by the sector as Chinese and Indian steelmakers clamour for New Zealand's high-quality cooking coal means it is a major economic driver in many small mining communities.
One such town is Greymouth, home to 15 of the Pike River miners, where grieving locals remembered the dead at church services Sunday.
At the Cobden Anglican Church, parishioners hung 29 small red paper angels, each bearing the name of a dead miner, on a Christmas tree, as thoughts turned to the 13 children who lost fathers in the disaster.
When the Pike River mine opened two years ago, local mayor Tony Kokshoorn hailed it as an economic saviour for the South Island's sparsely populated West Coast region sandwiched between the Southern Alps and the Tasman Sea.
Kokshoorn, who supports the eventual reopening of the mine, said Saturday that mining formed part of the community, which has recovered from other pit disasters, including ones in 1967 and 1896 that killed 19 and 65 respectively.
"We have to accept a history of disasters that go with coal," he told reporters.
Key said he would ask parliament Monday to set up a Royal Commission to probe the explosion at the colliery.
He said the Royal Commission - the most powerful investigation available under New Zealand law - would be headed by a judge and have wide-ranging terms of reference.
It would be the first Royal Commission to investigate a disaster since a probe into an Air New Zealand crash in 1979, Key said.
He said a Royal Commission had "gravitas and does demonstrate the significance of this national tragedy".
Pike River Coal estimates there are still 50 million tonnes of coking coal underground at the mine, a resource currently worth about 200 US dollars a tonne after being as high as 300 dollars a tonne before the global downturn.
The company's two Indian minority shareholders, Gujarat NRE Coke and Saurashtra Fuels Private Ltd, have contracts to buy 60 percent of its coal for the life of the mine, with China the other prime market.
Key said Pike River was unlikely to reopen until the Royal Commission determined the reasons behind the fatal methane build up, a process that could take more than a year.
But he added there was no need to immediately shut down the country's other underground mines, pointing out the nearby Spring Creek colliery had been operating for a decade without a major incident. A crowd of 73,500 at Cardiff's Millennium Stadium paid tribute to the miners with a minute's silence before New Zealand's rugby union Test win against Wales on Saturday. The All Blacks wore white armbands over their black shirts.