Wellington: An explosion ripped through New Zealand`s largest coal mine on Friday while about 30 people were underground, officials said. Five workers, dazed and slightly injured, stumbled to the surface hours later, while more than two dozen were missing.
Police said that shortly before the blast the electricity went out in the mine, which may have caused ventilation problems. That may have contributed to a build-up of gas underground.
The explosion was powerful enough to blow one driver off his machine deep in a tunnel, and one mine safety expert said gas was a possible cause of the blast, although spokeswoman Barbara Dunn stressed it was too early to say why it occurred.
Rescue teams and emergency workers rushed by helicopter and by road to the mine, located in remote and rugged mountains near the town of Atarau on New Zealand`s South Island. They cannot enter, however, before they make sure there is no gas build-up.
"They`re itching to get in there and start looking for other people and a bit frustrated at having to stand and wait," police spokeswoman Barbara Dunn said.
Tony Kokshoorn, the mayor of nearby Greymouth, told National Radio that it was unclear at what depth the explosion happened but that it was clear that it was very large.
Kokshoorn put the number of miners unaccounted for at up to 30. Peter Whittall, chief executive of mine operator Pike River Coal Ltd., said 27 people were missing — 15 miners employed by the company and 12 local contractors.
The coal seam is reached through a horizontal tunnel 1.4 miles (2.3 kilometres) in length that bores into a mountain toward the seam, which lies about 200 yards (meters) beneath the surface.
Whittall said five workers had walked out of the mine: a pair that included the machine operator who was blown off his vehicle one mile (1.5 kilometres) into the access tunnel. Three more came out later. One of the men had been able to make a call on his cell phone before reaching the surface, he said.
While the condition of the missing miners was not clear, the prospect that they could be alive but trapped recalls the dramatic saga of 33 Chilean mine workers who spent 69 days a half-mile (about one kilometre) deep in a collapsed gold and copper mine. They were rescued last month in an event played out on international television that captivated the world.
Energy Minister Gerry Brownlee said the explosion at the New Zealand mine happened at about 3:45 pm (0245 GMT, 9:45 pm EST) and the last contact with any of the miners was about half an hour later. They had not spoken to any of the missing miners during that time.
Two of the men who came to the surface were taken to a hospital for treatment of minor injuries.
"They`re being interviewed and we`re trying to determine ... the full nature of the incident," Whittall said.
It was not immediately clear if all of those underground were together or in separate groups.
"There is concern that ventilation inside the mine shaft may be compromised by the power outage," Dunn said.
Mine safety expert David Feickert said the blast could have been a gas explosion.
"There are different kinds of explosions that can occur in a coal mine — methane gas, coal gas and so on," he said. "If rescue teams can go in, that`s good news indeed."
St John Ambulance service said three rescue helicopters and six ambulances had headed to the mine. Rescue crews were assembled at the opening of the mine but had not yet entered as it was unsafe to do so until it was clear there was no build-up of gas.
Brownlee said emergency exit tunnels were built into the mine but that he didn`t know if they could be accessed by the miners.