Fire and emergency services have contained two scrub fires burning in the Waikato area this afternoon.
The fires, one on Kellyville Road in Mercer and the other on Island Block Road, were about a 15-minute drive apart. However, authorities said they believe they were related.
At its height, 15 fire trucks attended the blazes as well as two helicopters.
A spokesperson said both fires are believed to have started along the railway line and may have been train-related.
Authorities do not believe the fires were suspicious.
The blazes did not spread to the nearby Department of Conservation area.
Fire personnel have left the scene and will return in the morning to reassess.