Two crews from Rotorua Fire Brigade are attending a fire at the Rotorua Library.
A Fire North Comms spokeswoman said a fire alarm had been activated. Two crews were at the Haupapa St building and they had reported a fire in ducting on the third level.
Library programmes co-ordinator Karisma Vala said about 100 people had been evacuated from the building at around 4.15pm.
"It wasn't until we were outside that we noticed the smoke. It has quite a acrid smell to it which really sticks in your throat.
"People were very calm while leaving the building and there was no widespread panic"
Rotorua Daily Post's Stephanie Arthur-Worsop was at the scene and said it appeared the smoke was coming out of a chimney stack.
Another witness who did not want to be named said she was working on her laptop when the alarm sounded.
"We got told to evacuate and I asked if it was a drill because I couldn't see or smell anything. It wasn't until we were outside that it became obvious there was a real fire."