Southland Hospital's mental health facility was damaged by fire last night, but no-one was injured.
Three small fires had been lit and were quickly extinguished about 8.30pm, a Fire and Emergency New Zealand spokesman said.
Firefighters from the Kingswell station, Invercargill, ventilated the building, he said.
Southern District Health Board mental health, addictions and intellectual disability general manager Louise Travers said the affected area had been closed off and the damage would be assessed this week.
The fires were being investigated and the matter was with police, she said.
