Fire and Emergency NZ was called to a fire in a dryer at Winstone Pulp International's Karioi mill about 10.45am on Sunday.
Appliances from Ohakune, Raetihi, Waiouru and Taihape attended.
The fire was in a drying unit, and spread into the ceiling space, Fire and Emergency NZ Wellington shift manager David Meikle said.
By 2pm it was contained, but crews were still there, mopping up.
There was an earlier fire at the same mill overnight on October 11.
