Most firefighters have left Wellington children's hospital after a fire alarm prompted it to be evacuated.
12 fire vehicles from across the city were called to the scene at about 8.45am on Tuesday.
30 patients were moved to other parts of the hospital.
Fire and Emergency Assistant Commander Martin Wilby said a sprinkler went off which set off the initial alarm.
He said firefighters got readings on detection equipment which showed there had been a fire somewhere.
A small number of staff remain on site to search for source.
The hospital earlier said it had been evacuated over a possible gas leak.
Health New Zealand Te Whatu Ora Capital, Coast & Hutt Valley spokesperson Jamie Duncan said staff were alerted following the activation of fire alarms.
"All patients are in the process of being transferred to appropriate clinical spaces across Wellington Regional Hospital, and Fire and Emergency New Zealand are onsite as a precaution," he said.
There was no risk to patients, visitors, or staff, he said.