A 50-hectare fire has broken out in the Mill Creek area of Berwick, south of Dunedin.
Fire and Emergency New Zealand (FENZ) has five helicopters and 11 fire trucks responding to the blaze, which is burning through some tussock.
A FENZ spokesperson told Newshub the fire is on Department of Conservation (DoC) land and hard to access.
FENZ says the blaze is also being pushed by a southwest but isn't threatening any properties.
DoC southern South Island operations director Aaron Fleming said it was supporting FENZ to bring the blaze under control.
"It's too soon to say what any impacts could be," he told Newshub.
"The Mill Creek Scenic Reserve is primarily tussock and scrub and is home to native vegetation such as red tussock, wetland plants and other rare plants."
