Firefighters arrived at a factory fire in Motueka in the early hours of the morning to discover asbestos in the building.
Motueka residents were woken to the scary sounds of a large fire in the old industrial complex in the Tasman Bay town.
Fourteen fire trucks and support vehicles, including a command unit, responded to fight the fire at 4.30am on King Edward Street.
A Fire and Emergency spokesperson said the blaze was in an area without hydrants, so five tankers were at the scene.
Fire and Emergency assistant commander Chris Best said the presence of asbestos meant they had to fight the fire from outside the building.
"Asbestos being hazardous we've got to stay clear of the fire; we've got to ensure that our staff that are in the fire itself or involved in the firefighting are decontaminated and all our staff have been decontaminated at this stage."
Nearby residents were told to stay indoors and keep their windows closed to avoid inhaling the smoke.
Fire and Emergency said people should wash away any ash found on their property and rewash any washing hung outside as a precaution.
They said the blaze was not far from the main road in Motueka and there were other old factory buildings nearby.
A Motueka resident who lives about a kilometre from the blaze said she could see the orange glow of the flames from her window.
"About 4.30 [am] my husband and I were woken up by what sounded like fireworks but it just didn't stop.
"We could hear the popping and cracking like it was next door, it was so loud."
A fire investigator will assess the scene to determine the cause of the fire.