The fire at New World Victoria Park is not yet under control, with firefighters facing challenges in reaching the fire.

Crews were alerted by fire alarm activation to the fire around 11.18am. Currently there are 20 trucks and support vehicles are on the scene, with further resources still responding.

This includes the Hamilton aerial appliance, which has been deployed as backup for the three Auckland aerials already in use.

Incident Controller Vaughan Mackereth says the fire is currently burning on the mezzanine floor and in the roof.

"This means accessing it is difficult for our crews," he says.

"We are only fighting the fire from outside the building as it is too dangerous at this stage for internal firefighting.

"We are expecting to be here into the evening and overnight."

All persons have been accounted for.

The public is advised to continue to avoid the area, with the roads around the supermarket closed.

An Emergency Mobile Alert was issued for people southwest of the fire to stay inside with their windows and doors closed due to the smoke.

Fire Investigators are on scene but it is too early to speculate on the cause.

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