Wildfires have destroyed up to 50 homes in New Zealand, authorities announced Monday, saying it was a miracle no one was hurt as "a wall of orange" razed most of a remote South Island village.

The blaze began in a mountain forest early Sunday morning and, fanned by strong winds, swept through the village of Lake Ohau, forcing residents to flee for their lives.

Fire and Emergency New Zealand (FENZ) said the unpredictable winds made fighting the fire "challenging" and by Monday afternoon it had razed 4,600 hectares (18 square miles) of land.

Waitaki District mayor Gary Kircher said the tiny Lake Ohau community had been devastated.

"Of the 60 or 70 houses, we believe that the majority have gone," he told Radio New Zealand.

"The reality is that it's a minor miracle no one has been harmed. If it had been another 15-20 minutes it would have been a very different story."

Kircher described how residents awoke to find an inferno bearing down on them.

"I talked to a gentleman who got up to his dog (barking) in the early hours, opened his door and there was this wall of orange," he said.

"He was the one that set off the town fire alarm and helped to wake people ... there's certainly some scary tales about how close it came to being an absolute disaster with fatalities."

Wildfires are relatively common on the South Island at this time of the year but the scale and intensity of the Ohau fire have been unusual.

By Monday afternoon the fire front had moved far enough from the village to allow evacuated residents a brief trip back to assess the damage.

Civil Defence Minister Peeni Henare, who accompanied them, described seeing burned-out cars and gutted homes.

"The term I've heard used to describe it is a 'war zone,'" he told reporters.

"It's clear to me that there's no rhyme or reason when it comes to fire; one house is affected, the neighbor isn't ... you can feel a sense of loss."

FENZ said 11 helicopters and eight fire crews were attempting to contain the flames.

With light rain forecast for the next 24 hours, there were hopes it would be under control by Tuesday night.

New Zealand this year experienced its warmest winter on record, which the National Institute of Water and Atmospheric Research (NIWA) said was consistent with a long-term trend of rising temperatures linked to climate change.

Professor George Perry, an environmental science expert at the University of Auckland, said it was difficult to attribute a specific event such as the Lake Ohau fire to climate change.

But he said New Zealand had experienced more large wildfires than usual in recent years, pointing to changes in the three main factors affecting wildfires – fuel, climate and ignition sources.

"We would expect more such events under climate change especially as conditions become warmer and drier, and we see more droughts," he told Agence France-Presse (AFP).