Passengers on the Half Moon Bay ferry were evacuated after an incident in the engine room.

Emergency services responded to the incident in downtown Auckland this evening.

Commuters say they understand there was an issue with the generator and gathered on Quay St.

About 100 passengers had their commute disrupted as they waited for the next ferry.

Shortly after evacuating the passengers, a Fullers staff member allowed people back onto the jetty to wait for another ferry.

Fullers360 CEO Mike Horne said a fire alarm alert was raised onboard the 5.40pm sailing designated for Half Moon Bay this evening but it has since been confirmed there was no fire onboard.

Horne said an issue with the vessel’s exhaust system caused smoke and some steam, which triggered the onboard fire sensors.

“We apologise to customers on board for any disruption caused by this incident,” Horne said.

 “Safety is our number one priority, ensuring customer and crew wellbeing onboard. This is an isolated event, and we will continue working with authorities to investigate and resolve the cause of the issue.”

He also said the ferry will undergo a full maintenance and safety review under Maritime Regulation before it is cleared to return to service.