Fire has destroyed three shops and badly damaged a fourth in the main street of Dargaville.
It took 100 firefighters and 19 appliances more than two hours to bring the blaze under control on Monday night.
The Fire Service was alerted shortly after 7.30pm.
No one was injured, but a decorations shop, a video outlet and a paint store were badly damaged.
Dargaville chief fire officer Mitch King says bedding, furniture and paint in the shops helped to fuel the flames.
A section of the main street is still cordoned off.