Auckland fire: Thousands evacuated in New Zealand after blaze breaks out at SkyCity convention centre

Thousands of people were evacuated in Auckland on Tuesday after a huge fire tore through a convention centre.

Emergency services scrambled to the under-construction building, but there were no reports of any injuries and the owner of the site said everyone had been evacuated.

Black smoke rose up into the skies above the central business district, prompting New Zealand health authorities to warn residents to take precautions against smoke inhalation.

Around 23 fire trucks had joined the operation to bring the blaze at the SkyCity convention centre under control, Fire and Emergency New Zealand said.

Traffic was gridlocked in the downtown area as the emergency services flocked to the site, and roads were blocked off, and people were advised to stay away.

The nearby Sky Tower, New Zealand's tallest building, was shut and media reports said hundreds of hotel guests in the area were stranded.

"There have been no reported injuries," SkyCity said on Twitter, adding that everyone had been evacuated from the convention centre.

The spokesman said that Sky Tower and a casino had been closed until further notice.

There was no immediate official word on the cause of the fire or how many people had been at the centre when the fire broke out.

"It's a very, very difficult fire to extinguish," Fire and Emergency spokesperson Dave Woon told reporters earlier on Tuesday.

"We are not on top of the fire but with the resources that have just arrived we should be able to make progress.

"We don't have any injuries at the moment and we don't have anybody missing."

Witnesses posted videos of the blaze on Twitter.

"Fire is really building," Auckland's mayor, Phil Goff, said on Twitter shortly after the fire broke out. "People can be seen on the roof."