Five fire crews are trying to control a fire raging in an industrial building in Nelson.
Two crews from Stoke and Nelson were alerted to the blaze at 4.13am in a 10x15m building on Pascoe St in the suburb of Annesbrook.
They received extra support from Stoke, Nelson and Richmond crews shortly after.
A Fire and Emergency spokesman said nobody was injured and there were no indications anybody was in the building.
"There is no indication of cause. At this stage the operation continues."
They were yet to establish what the property was or who owned it, he said.
The building had already been extensively damaged when the crews arrived.
"It was well ablaze when the fire crews got there. The brigades could see it from neighbouring streets."
Firefighters will continue working through the morning to control the blaze.