A Mine Disaster in New Zealand

Twenty-seven miners remained trapped underground Friday night after an explosion at a remote coal mine on New Zealand's South Island, with rescue attempts delayed by concerns about air quality in the mine.

Late Friday, two miners who had managed to exit the mine were in the hospital. But Saturday morning, police officials said they still hadn't managed to reach any of the miners.

"At this point we are unable to get into the mine because of the quality of the air," said police spokeswoman Kaye Calder Saturday, who added that mine experts had been testing the air quality overnight. "We have had no contact with the people inside the mine," she added.

The incident comes five weeks after 33 trapped miners were freed from a Chilean mine after more than two months underground. A week after that rescue, 37 miners in China died following a gas explosion in a mine.

"There are 27 men underground, and two men have walked out," said Peter Whittall, chief executive of the mine operator. "The other employees are further into the mine, … and at this stage we haven't had any contact with those employees."

Of the 27 men underground, 15 work for Pike River Coal and 12 were contractors. The drill operator was a foreigner, while the rest were believed to be New Zealanders.

Mr. Whittall said he didn't know what caused the explosion. There could have been a coal-bed gas explosion, but that wouldn't be known until rescue teams reached the workers, he said.