The explosion occurred around 4.30pm on Friday, with two miners emerging from the mine disaster shortly afterwards.
Both were unable to provide much information on what had transpired. Ventilation systems were damaged and offline because of the explosion.
Search and recovery operations have not started due to the fear of losing lives, with high gas levels throughout the weekend.
The rescue effort now awaits the completion of a drillhole started yesterday.
Pike River chief executive officer Peter Whittall told the Daily Post the team drilling the hole had reached 100 metres of the planned 162m overnight.
"In the last 10 metres before we get to the scene we will change drilling method to ensure we don't get any sparking," he told the newspaper.
"We have opportunities to sample gas from that point. We will have an opportunity to put laser imaging gear down the hole.
"We will also be able to put down video camera information and look at anything we are able to see in the hole."
He told the newspaper there was an unsafe incident at the time of the blast, “otherwise this would not have occurred”
Yesterday Whittall said if the ground the drill bit passes through is not stable, the hole will need to be encased to prevent its collapse – which would slow progress.
Importantly, the drillhole will allow more gas samples to be taken, with gas levels only sampled from one ventilation point so far, providing inconclusive results.
With the eyes of the world on the mine, Whittall said it was an emotional time for the relatives of the missing miners.
The two men who emerged from the blast, an electrician and a loader driver, both indicated that three others were on their way out according to the New Zealand Herald.
ILN understands that Pike’s miners are instructed to walk out of the mine with
self-contained self rescuers under their emergency procedures, with refill caches also placed in escapeways in the mine.
A MineArc spokesman confirmed it did not have any refuge chambers at Pike River, but did have them at Solid Energy’s Huntly East underground coal mine on New Zealand’s North Island.
To the procedural strategy of immediately exiting a mine under an emergency, he told ILN the counter argument was “what if” the miners were blocked off or trapped?
During a televised media conference on Saturday, Whittall did not rate the Pike mine as gassy compared to mines he had worked on in Australia.
Whittall was general manager of the mine since 2005 and was promoted to his senior position on October 2, taking over from long-time CEO and managing director Gordon Ward who unexpectedly resigned in September.
Before working at Pike, Whittall had 24 years of experience with BHP Billiton Illawarra Coal, including managing the Dendrobium, Tower and Appin mines in New South Wales.
Shortly after the explosion on Friday, Engineering, Printing and Manufacturing Union national secretary Andrew Little told ILN gas was an issue for a lot of the West Coast mines.
“Some are more gassy than others, it’s a pretty big risk on a lot of those seams on the West Coast,” he said.
Pike performed in-seam drilling for gas drainage purposes.
The mine had a workforce of about 180 according to the September quarterly report, and nine trainee managers had been appointed to provide a 12-week training course.
“After five weeks, trainees go onto shift and work under close supervision on crew while continuing their practical and theoretical training,” the company said last month.
The names, ages and nationalities of the missing miners were provided by NZ Police:
Conrad Adams 43 (NZ), Malcolm Campbell 25 (Scotland), Glen Cruise 35 (NZ), Allan Dixon 59 (NZ), Zen Drew 21(NZ), Christopher Duggan 31 (NZ), Joseph Dunbar 17 (not disclosed), John Hale 45 (NZ), Daniel Herk 36 (NZ), David Hoggart 33 (NZ), Richard Holling 41 (NZ), Andrew Hurren 32 (NZ) Jacob Jonker 47 (South Africa), William Joynson 49 (Australia), Ricki Keane 28 (NZ), Terry Kitchin 41 (NZ), Samuel Mackie 26 (NZ), Francis Marden 41 (NZ), Michael Monk 23 (NZ), Stuart Mudge 31 (NZ), Kane Nieper 33 (NZ), Peter O'Neil 55 (NZ), Milton Osborne 54 (NZ), Brendan Palmer 27 (NZ), Benjamin Rockhouse 21 (NZ), Peter Roger 40 (UK), Blair Sims 28 (NZ), Joshua Ufer 25 (Australia), and Keith Valli 62 (NZ).
Pike shares remain in a trading halt.