As tensions rise in the tough, tight-knit, west coast community, police warn that worries about toxic gases, fires and further explosions are preventing them from rescuing the men, including two Australians, who have been missing since Friday afternoon.

Tony Kokshoorn, the mayor of Greymouth, says family and friends of the missing are distraught. ''People are starting to despair, it's on their faces,'' says Mr Kokshoorn, who implored police to release the names of the men to end the speculation and ''Chinese whispers''.

Many are reported to be impatient, some angry at the lack of progress. Mr Kokshoorn is sympathetic. He understands police and rescuers are ''between a rock and a hard place'', but says inaction is also dangerous. ''To do nothing too, is not wise either."

But there was at least some progress. Yesterday, relatives of the missing men, 24 New Zealanders, two Australians, two Britons and a South African, were given a private briefing and a two-hour bus tour of the site.

They are believed to have included the family of the one Australian named, Queenslander Josh Ufer, 27, who was recently told by his girlfriend Rachelle he is to become a father.

The families are ''really gratified, really pleased, in fact rapt'' at being allowed to see the rescue operation and ''understand the situation a little bit better'', Mr Kokshoorn says.

Mr Kokshoorn says the  rescue team is going to put a laser camera down a bore hole currently being drilled into the mine, at a depth of 150m.

Authorities continue to assess the risks in sending in rescue teams on standby but emphasise they hope to find the miners alive.

''This is not a quick fix. We've no idea how long this will take, but we're still focused on bringing these guys out,'' says police commander Gary Knowles.

But he is not prepared to risk losing the lives of a further 16 men by making ''a half-arsed rescue attempt'' in conditions markedly more dangerous than those in gold or copper mines, such as that in Chile where 33 men survived for 69 days.

Trevor Watts, the general manager of NZ Mines Rescue, says there is no shortage of manpower, expertise and equipment. Experts from Australia and elsewhere were advising on site, while an eight-man NSW rescue unit remains on call in Christchurch.

''We have more equipment than we know what to do with,'' he says.

While the main concern is the potential for explosion, the logistics of deploying men underground are also daunting. ''This is not like walking down to the local supermarket,'' Mr Watts says.

The terrain is uneven, the temperature unknown. Rescuers will need heavy breathing apparatus and will have to walk for two hours to where the miners are believed to be trapped about 120 metres underground, two-thirds of the way into the 2.3 kilometre tunnel.

''We are still in the gun barrel. You put a bullet at one end of the gun, it's going to come out the other end,'' says Mr Watts, who believes there may have been a fire in the tunnel since the original explosion.

His caution is echoed by Paul Healey, NSW Mines Rescue general manager. ''Team protocols insist all data related to risks must be understood and within acceptable range before proceeding. This is sometimes a slow and frustrating process, but experience has shown that it is necessary.''

Anxious friends and relatives sought solace at the bowling club yesterday, in the church, the Red Cross emergency centre and in each other's homes, shunning the international media that has been flooding into the town of about 10,000.

West coasters hate the ''overseas perspective'', reporters who drop into town after a tragedy, interview someone in a bush shirt at the pub, and then go home, said Paul Madgwick, editor of the Greymouth Evening Star.

Madgwick says every staff member knows someone trapped underground. ''This place is so bloody small. Everyone here - it's either your friend, your family, your neighbour.''

Getting a job at the mine, he says, has been likened to a Lotto win. ''So many people, young family men with little kids and babies … have been tempted out to Pike River by the big bucks''.

Now, everyone is hanging on every word spoken by the authorities, trying to find a little bit of hope. But as Madgwick says, ''there is not a lot to grasp on to''.