Firefighters are battling two separate blazes near Christchurch's Port Hills, amid fears they could join and create one massive scrub fire.
At least one helicopter and four appliances are battling one blaze near Summit Rd in Governor's Bay, which broke out around 7pm.
Houses on Summit Rd have been evacuated, and it's understood the fire service is evacuating some crews due to safety concerns.
Meanwhile, crews from all over Christchurch have been tackling a large scrub fire on Early Valley Rd south of Halswell on the other side of the Port Hills.
Eight appliances, three tankers and four helicopters are fighting the blaze, which has destroyed one house.
One helicopter is searching the area for any people trapped that may need evacuating.
During daylight, plumes of grey smoke could be seen spreading out across the city as far as Lyttelton.
One resident leaving the area said she didn't know what the fate of her house was.
"I was at home [and] saw the smoke so I came down the hill," she said.
"It's pretty scary, it's quite a big fire."
Another said she saw flames within metres of her house and only had time to leave with the clothes off her back.
Police say some residents have self-evacuated from their properties, while others have been asked to leave.
Those evacuated are being moved to Tai Tapu School where they may stay overnight.