A public fireworks display in Auckland was cut short last night after hot embers started showering down on thousands of people gathered to see the spectacle.

At least four people were treated by ambulance staff with suspected eye injuries and one woman taken to Auckland City Hospital, when an unexpected wind shift caused sparks to drift back on the packed crowd watching the anniversary weekend display.

At the time the Captain Cook Wharf was at capacity, with an estimated 6000 people watching an evening concert by the Auckland Symphony Orchestra that ended with an explosive eight-minute-long pyrotechnics finale.

But midway through the closing, rousing refrains large sparks began falling across the darkened wharf, injuring a handful of people looking skyward.


As people left the packed wharf, injured spectators were seen lying on stretchers in waiting ambulances, their eyes covered with large white eyepatches.

Ports of Auckland spokesman Matt Ball today confirmed a small number of people with minor eye injuries were taken to hospital.

They needed to have their eyes flushed after being injured by stray sparks from the fireworks.

Mr Ball said a number of precautions were taken ahead of last night's display including safety zones to keep the public well back from where the firework display was set up at the farthest end of the wharf.

However, an unexpected change in wind direction during the pyrotechnics put the public at risk and a decision was taken to end it prematurely.

Organisers also moved the massive crowd back during the display to try to protect them from being burned.

"After the fireworks started the wind picked up and a few showers of sparks fell down on the people," he said.

"A small number of people got hit.

"It's just unfortunate the winds picked up during the display."

A St John Ambulance spokeswoman confirmed four people were treated for injuries at the event.

At least one person was taken to hospital for treatment, she said.

She was unsure about what they had sought treatment for but said all the injuries were possibly minor.

An Auckland District Health Board spokesperson said a woman was brought from the event to Auckland City Hospital with an eye injury.

She was treated in the emergency department and discharged.

Last year Van Tiel Pyrotechnics pleaded guilty to seven charges laid by WorkSafe and was fined $100,000 after three spectators were injured during a fireworks display at Eden Park during a 2014 All Blacks test match.

The company that ran last night's fireworks display, Auckland-based Boom Boom Fireworks, could not be reached for comment.

WorkSafe New Zealand said it had not received any notifications related to the fireworks display.