Update: 1.02pm:
Rescuers have evacuated all 28 miners who were trapped by a fire inside the Waihi Gold underground mine.
A truck engine caught fire in Newmont Waihi Gold's Trio underground mine at about 5am, leaving the men trapped in three refuge chambers.
Mines rescue staff had evacuated thirteen of the
miners by 10.30am, while 15 remained trapped in a rescue chamber deep in the mine.
Waihi Gold general operations manager Glen Grindlay said the remaining men were rescued by 12pm after seven hours in the chamber.
One man would seek medical attention for smoke inhalation, he said. There were no other injuries.
"All are in good spirits, they're very happy actually, Mr Grindlay said.
"I believe some of them thought it was a drill."
Mr Grindlay said the fire in the mine was now "contained to a stock pile".
The 35 tonne Komatsu truck had burnt out while rescue teams sought to get to the trapped men, he said.
"We opted to go for the personnel first and worry about fire later".
The cause of the fire was unknown, Mr Grindlay said.
"This will obviously be the focus of our investigation at a later stage."
Mine spokesman Kit Wilson said the miners had followed procedure by heading to rescue chambers when the fire broke out.
"In coal mines you get out. In gold mines you wait it out."
Family members are gathering at the mine as their loved ones are slowly evacuated.
Counsellors are on site to speak with the men and their families. Some of the men have already left in vehicles either to meet with family at another gathering point in the township or to go home.
DEBRIEF TO FOCUS ON PROCEDURE - UNION
Engineering, Printing and Manufacturing Union assistant national secretary Ged O'Connell said the final 15 miners reached the surface shortly before midday.
"We're very, very relieved everyone's out unscathed,'' Mr O'Connell said.
"They're now entering into a debrief situation over the next hour or so and they've invited us [the union] into it to just consider how the evacuation process went.''
Mr O'Connell said the debrief would help evaluate how the miners reacted to the truck fire and how effective the evacuation procedures were.
"We're not rushing into finding out the cause [of the fire] at this stage. The key thing for us is to ensure the evacuation procedures went well and it appears they did,'' Mr O'Connell said.
He said part of the debrief would be speaking with the miners about how they are coping.
"Part of that ... is what are their needs, whether they need to take time out, how they are coping.''
Mr O'Connell said a lot could be learned from the evacuation.
"Particularly the fact that there has been no casualties ... it is a chance to get stuck in now and do a detailed debrief and learn as much as we can about the situation. Were there good procedures in place? Were people aware of them? Did they go with [the procedures]? How effective were they?''
Update: 12.35pm
Family members are gathering at the mine as their loved ones are slowly evacuated.
Counsellors are on site to speak with the men and their families.
Some of the men have already left in vehicles either to meet with family at another gathering point in the township or to go home.