The Defence Force has confirmed a large fire west of Christchurch began while soldiers were conducting training exercises.
At its height, 60 Fire Service and 40 police personnel, six helicopters and 18 ground-based fire appliances were used to contain the scrub fire near West Melton.
Six homes had to be evacuated along with the West Melto Aero Club and a group from the Riding for the Disabled organisation.
The Defence Force said it would conducting its own investigation into the fire, which began at 12.30pm on Wednesday and had been contained by 5pm.
Major Bill Blair, the commandant at Burnham Military Camp, said the blaze began on the Army-owned rifle range after troops had been carrying out grenade-throwing exercises.
He said a fire crew is always present at live shooting exercises, but the flames moved too quickly to control straight away.
A fire crewman was injured and a fire engine superficially damaged.
Major Blair said it is almost certain that a court of inquiry will be held over the incident.
There have been several fires in West Melton in recent weeks and hotspots from prior fires still exist.