Sun Nov 28, 2010
The first mine explosion at the remote South Island pit happened on November 19.
A 4th underground explosion has rocked the Pike River Mine in New Zealand's south island, where 29 miners earlier perished.
Police say there were no injuries when the gas explosion occurred just before 2:00pm local time on Sunday Nov 28.
People who were working close to the mine entrance were moved to a safer distance.
Police say this fourth blast demonstrates the ongoing volatility of the site.
Twenty-four New Zealanders, two Australians, two Scots and a South African died in the mine near Greymouth.
One New Zealand news agency is reporting that this fourth explosion blew away some of the infrastructure on top of the shaft.