Up to 30 miners are trapped in the Pike River Coal Mine on the West Coast after an underground explosion this afternoon.
Energy Minister Gerry Brownlee said the blast happened at 3.45pm and the last contact with any of the miners was lost at 4.15pm.
He said mine officials had no idea what caused the blast, or the condition of the miners who were trapped.
A Herald source said there were in fact 36 people, made up of miners and management, who were on a safety tour, trapped in the mine.
Two miners have emerged from a service portal in a separate part of the mine, and are being interviewed by mine managers and emergency services.
The Mayor of Grey District, Tony Kokshoorn, told Radio New Zealand 25 to 30 people were unaccounted for, saying "it's not good".
Police, ambulances and helicopters are at the mine.
There's not a heck of a lot that one can say at a time like this. It's great that two miners have emerged safely, and we can only hope and pray that all of those who are trapped will be freed and returned to the surface safely and soon.
We'll update as further news comes to hand ...
UPDATE: TVNZ is reporting that there has been at least one fatality at Pike River