Police believe there is no chance of any of the trapped 29 miners surviving the second massive explosion in New Zealand South Island's Pike River Coal mine on Wednesday.

Family members of miners trapped underground in the Pike River coal mine react after learning of a second explosion in the mine at a briefing by mine authorities and police in Greymouth on New Zealand's west coast November 24, 2010. (Xinhua/Reuters Photo)

"Unfortunately I have to inform the public of New Zealand at 2. 37 p.m. today there was another massive explosion underground and based on that explosion no one would have survived," Knowles said.

"I was at the mine myself when it actually occurred and the blast was prolific, just as severe as the first blast (last Friday) ," he added.

Knowles said he was with a rescue team when the blast happened and they were in agreement with him that the miners would have " perished".

Police said there is now no chance of the miners being alive and they are going into recovery mode.

The 29 men have been missing since the first explosion on Friday afternoon.

Grey District Mayor Tony Kokshoorn, who was at the civic center when the news was broken to the families, said "this is the West Coast's darkest hour".

He said the news had been "sickening", and families were devastated.

The families and communities of the dead miners have been changed forever by Wednesday's catastrophic blast, he said.

"This has got to be the darkest day for me, for Greymouth, for everywhere," he added.

He said families fell to the floor when they heard the news.

Pike River Coal mine chief executive Peter Whittall told a media conference that it was still unsafe for a recovery team to enter the mine.

Whittall said monitoring of gases through a bore hole prior to the explosion revealed methane concentrations of 95 percent.

Gas testing would continue, he said, because the mine remained as unsafe as before.

VietNamNet/Xinhuanet