Firefighters were battliing a scrub fire on Campbell Rd in Brunswick near Whanganui on Tuesday.
Multiple fire crews were at the scene as well as a helicopter with a monsoon bucket.
The fire appeared to be burning in a large valley, with large areas of burnt scrub visible.
A Fire and Emergency NZ spokesman said a burn-off has got "a bit out of control" and crews are trying to find the best entry point to combat the blaze.
Crews were alerted just after 2.30pm to the 30m by 10m fire.