Up to six helicopters are battling a large blaze in Canterbury's High Country.
It's too early to know what started the fire which is burning through hundreds of hectares in Broken River, an area popular with hunters.
The enormous blaze, which has burnt through a vast area of vegetation, started on Friday and is still burning - stretching over 300 hectares at its peak.
The fire is in remote, rough terrain with six helicopters attacking it by air backed up by ground crews from Fire and Emergency New Zealand and the Department of Conservation.
"As you can tell by the conditions, we're dealing with quite stiff northwesterly winds," says Fire and Emergency NZ's Tim Reynolds.
Fire and Emergency NZ is warning hunters and trampers in the High Country to take extreme care with anything that can cause a spark or a fire.
"It's a bit early to tell what the cause is yet. We do have two specialist fire investigators on scene trying to determine that now," says Reynolds.
There's a small historic hut in the area used by trampers and hunters but crews have worked hard to keep it safe.
"Our priority is to get the flanks of the fire secured as much as we can so we limit the growth of any fire in the coming days."
Helicopters will be back up here on Sunday working again until they win the battle against the blaze and get it completely contained.