The New Zealand Defence Force will investigate how a live ammunition training exercise at an Army base near Christchurch caused a large scrub fire today.
The blaze started at Burnham Military Training Area at West Melton about noon, whipping through scrub and threatening nearby homes.
Sixty firefighters, up to six helicopters, 18 ground-based appliances and 40 police staff were involved in the response to the incident, which covered an area about 1km by 500 metres.
One soldier suffered minor injuries trying to put the fire but there were no other injuries or reports of damage.
The fire was contained by early evening and firefighters from 10 appliances and Defence Force volunteers were preparing to work through the night.
Incident controller Sergeant Greg Fagg, of the 3rd Emergency Response Troop based at Burnham Military Camp, confirmed there was rifle training for infantry soldiers today.
"As a result of our training activities a fire has started."
Sgt Fagg said the exercise was on a gravel area and there "theoretically shouldn't have been any fires starting there".
The blaze had "got away" from a firefighting appliance that was on site.
Mr Fagg was unsure whether live firing or explosions sparked the fire, which did "exactly what it shouldn't have done".
"The cause of the fire will be determined by investigation and from that we'll determine if our measures for fire control need to be revised.
"However, it's just one of those things, you plan for it ... but something happens that is out of the norm."
The training area is in an area that has been plagued by scrub fires over the past fortnight.
The land is largely browned off, extremely dry, and the Fire Service has warned against fires in the area.
Defence Force spokesman Major Aidan Shattock said an assessment of environmental conditions, including fire risk, must be completed before live firing is carried out and anyone firing must adhere to safety procedures.
"They'll get approval from the fire master to conduct their firing in that location and once that's done then they can carry on with their live firing. If anyone fires on that range they have to abide by those rules," he said.
Houses near West Melton Airport were evacuated and nearby property owners told to prepare to leave as fire crews struggled to control the blaze fanned by hot, dry nor-west winds.
Old Coast Rd resident Kevin Righton, 62, was preparing to flee as the fire neared his home.
"I'm panicking a bit. We're just a kilometre down the road and the wind has really picked up," he said.
But by 4.30pm the fire was largely contained, although firefighters and police continued to fight the flames last night, keeping a close eye on wind conditions.
- APNZBy Kurt Bayer @KurtBayerAPNZ Email Kurt