Check here for today's developments in the wake of the Pike River mine disaster.
5.39pm: That brings us to the end of our live updates for the week.
4.50pm: A third explosion has taken place at the Pike River mine this afternoon almost exactly a week after the initial blast.
Police District Communications manager Barbara Dunn said the blast occurred at 3.39pm and lasted for 23 seconds.
Company chairman John Dow said nobody was at the mine at the time.
The blast confirmed the volatility of the environment, he said.
"This was always a possibility."
4.11pm: Pike River Coal Chairman John Dow says the Pike River mine will not be a coal mine "for a while".
"Clearly the site has value, it has the ability to be rebuilt but until we understand exactly what the scale of damage is underground it is hard for me to say how much that might cost and how long it might take," Mr Dow said at a media conference in Greymouth today.
He said the mine would not be reopened nor would any attempt be made to recover the bodies, until it was safe.
Mr Dow pledged Pike River Coal's full cooperation with any inquiry.
3.58pm: A senior ACC member has been sent to Greymouth to help families affected by the Pike River mine tragedy, ACC Minister Nick Smith says.
Dr Smith said the Pike River disaster is expected to be the biggest claim for a workplace accident in the history of the scheme, and ACC is well prepared for the rush.
"It is able to lodge claims based on basic information, does not require specific forms, and will not be awaiting any inquiry to get support to the families
"ACC has already deployed a senior staff member to Greymouth to assist the families and help ACC staff in the town. It has put together information packs for the families that have been made available," he said.
Families of the Pike River workers are eligible for up to $5541 in funeral grants, a one-off payment of $5940.91 for a partner and $2970.47 payment for each child under 18.
Weekly compensation payments based on a percentage of earnings can also be made, and child caregivers could receive payments for each child for up to five years or until the child turns 14.
3.44pm: A week on from the first explosion at the Pike River, emergency crews and staff at the mine are observing a moment of silence to remember the 29 men who lost their lives.
"We'll assemble all of the emergency crew and men at the site and have a minute's silence for our friends still in there," Pike River chief Peter Whittall told Sky News.
He requested others "check their watches" and join with them to commemorate those who died.
Families will be taken up to the mine site again tomorrow, where the company will display photos, including the tag board indicating the 29 are still underground.
3.24pm: Video footage taken from a robot has confirmed the second blast at Pike River was more intense than the first.
"There's a lot more destruction in there now than there was after the first blast," Pike River chief executive Peter Whittall says.
The secondary explosion had been a "much more violent blast", he said.
3.08pm: Pike River Coal chairman John Dow has told a press conference the company has two "business interruption" insurance policies, with $100 million of coverage.
Work was underway to lodge those claims now, he said.
Both of the company's main lenders, the BNZ and major shareholder New Zealand Oil and Gas had agreed to extend loan repayments dates until the end of February and had suspended interest payments.
Dow said while there still needed to be an assessment of damage underground to the mine, there was significant infrastructure - including roads, water pipes, offices and workshops that were undamaged.
"My view of it is that Pike River would be considered an advanced development project. Clearly we won't be a coal mine for a while, but equally clearly this site has value, it has the ability to be rebuilt, but until we understand what the scale of damage is underground it's hard for me to say how much it might cost and how long it might take," he said.
2.52pm: Pike River Coal will conduct its own inquiry into an explosion that killed of its 29 miners.
The company's chairman, John Dow, announced the inquiry this afternoon, saying Pike River would also co-operate with a Commission of Inquiry, investigations by police and the Department of Labour and coronial inquiries.
The inquiry is an attempt to "get to the bottom of this terrible accident", he said.
2.23pm: The chief executive of Pike River Coal, Peter Whittall, has asked people in Greymouth and around the country to observe a minute's silence at 3.44pm today - one week after the initial blast at the mine.
Mr Whittall said he and Superintendent Gary Knowles would assemble with emergency services and rescue teams at the mine site in just over an hour to pay their respects.
He said local iwi had performed a karakia at the mine site this morning, a moment he described as "powerful".
Mr Whittall also revealed in a press conference this afternoon that a third robot had gone 1575m into the Pike River coal mine and detected debris and destruction in the main shaft that indicated Wednesday's explosion was much more violent than the first one last Friday.
2.00pm: Good progress is being made on plans for the recovery of the victims of the Pike River mine blast, police say.
Superintendent Gary Knowles said a team of specialists was working on the operation.
"They are working as quickly as possible to develop and confirm options. Throughout all this, the safety of the people involved is our paramount concern. There is no time frame for decisions at this point.
"Our priority is to stabilise the mine environment so that we can then mount a recovery," Mr Knowles said.
1.28pm: Police Minister Judith Collins said that after rescue operation head Superintendent Gary Knowles spoke to the miners' families today they applauded him.
Mr Knowles has been the target of criticism in the past few days.
"I would like to think it is a sign it is a sign of appreciation because they know that he shares a great deal of their pain and that he has to lead a very difficult matter in the most extraordinary circumstances," Ms Collins said.
When the families were told the national memorial service had been confirmed, they also applauded, she said.
12.44pm: A memorial service for the 29 miners who lost their lives in the Pike River Mine tragedy will be held next week.
The service will be held at 2pm on Thursday, December 2, at the Omoto Racecourse, near Greymouth.
Organisers are preparing for a minimum of 5000 attendees and there are plans to broadcast the service live on television and radio.
Prime Minister John Key said the service would be "a chance for New Zealanders to gather together to remember and mourn the men who tragically lost their lives in one of the nation's worst disasters".
12.36pm: More than a million dollars and thousands of text messages pledging donations have poured into the Pike River miners' relief fund.
The donations to the Grey District Council have come from banks, local organisations and individuals.
Council finance manager Ian Young says money for the victims' families is constantly rolling in, with the tally currently standing at around $1.3 million.
Mr Young says the messages coming in with the 30,000 texts received so far are heartfelt and supportive. Each text donates $3 to the fund.
11.14am: A jet engine which will suck oxygen out of the explosive Pike River mine in a bid to make it safe to enter could be up and running by Monday, the head of New South Wales Mines Rescue services says.
The engine arrived early this morning and is already at the mine site, but would take up to three days to set up, NSW state manager Seamus Devlin told Radio New Zealand.
11.07am: Rail and maritime workers have passed on their condolences to the families and colleagues of the 29 miners and contractors killed at Pike River.
Rail and Maritime Transport Union (RMTU) General Secretary Wayne Butson said RMTU members on the West Coast were shaken by Wednesday's news.
"Our 88 members on the Coast were devastated. We work closely with the miners at the coal load sites," Wayne Butson said.
"We express our sympathy and solidarity with the families of the miners who died, and other miners who are now grieving for their lost workmates."
10.17am: International Mines Rescue Body secretary Alex Gryska said the world would be watching an investigation into the tragedy, which claimed the lives of 29 men.
Mr Gryska said he would not expect a disaster of that magnitude in New Zealand.
"Having incidents like this in developing countries is one thing. Having it happen in western countries is uncommon."
9.06am: Mines Rescue workers remain united in their desire to get their 29 brothers back, their leader says.
"However long it takes, our men will be there to do their very, very best to recover these guys," New Zealand Mines rescue general manager Trevor Watts said.
They were preparing for a "tough and difficult task", he told TVNZ.
"We will minimise the risk as much as we possibly can, but our men are still going to be faced with hostile conditions," said Mr Watts.
8.35am: Mining safety expert David Feickert says recovery of the 29 men killed in the mine tragedy is likely to take a long time, and grieving relatives need to be patient.
It was important families worked with available support services to deal with their grief while waiting, he said.
"The trouble with mining, it's a mixture of science and arts, and this will apply in this case as well," he told Radio New Zealand.
"... the science is quite good in these situations but there needs to be a lot of art and a considerable amount of intuition in handling it. This is the way mining is.
"They will need to be patient, it's not something that can be rushed."
8.12am: West Coast miners knew their 29 mates at Pike River were a lost cause before the official announcement on Wednesday, a union convener in Solid Energy's nearby Spring Creek pit says.
"The initial explosion wiped out all the infrastructure," said Trevor Balderson, a night-shift development worker who heads a crew of six at Spring Creek, 40km from Pike River.
"If you talk to any coal mine workers anywhere in the world, the reality is that you do not survive an explosion if you are in the firing line," he told a British newspaper.
Scientists had estimated the fireball which ripped through the mine last Friday probably reached temperatures higher the 1200degC.
7.43am: Cabinet will discuss setting up a Commission of Inquiry on Monday and Prime Minister John Key said he anticipated it would include at least one Australian mining specialist.
"It will certainly have a judge, we need to work our way through it," he said last night.
"We need to satisfy ourselves that the environment is safe, that coal mining in New Zealand is safe."
Mr Key said the first thing that had to be established was what went wrong.
7.30am: A crowd of 50,000 at last night's U2 concert in Auckland heard lead singer Bono pay tribute to the 29 Pike River coal miners.
"My privilege is to play for you in this week of all weeks and at a time like this when your hearts must be so aching and so raw."
7.15am: A memorial service for the 29 dead Pike River Coal miners will be held at the Omoto Racecourse near Greymouth.
The Prime Minister will attend the service, as will a number of dignitaries from New Zealand and overseas. The service will be broadcast live.
The Prime Minister's office said the date of the service is still to be finalised.
7.00am: Good morning once again. Today, officials are considering a drastic, high-tech strategy to recover the 29 bodies inside the Pike River Mine.
A large jet engine which stabilises gases has arrived from Australia.
The engine would force liquid nitrogen or liquid carbon dioxide into the mine to stabilise the atmosphere. Over time this starves the fire of oxygen and eventually smothers it.
Despite a brief stabilisation in the mine on Wednesday night, the 2.8km network of tunnels has refilled with potentially explosive methane and poisonous carbon monoxide.
- NZPA, NZ HERALD STAFF, NEWSTALK ZB
