Nightfall has highlighted the intense flames continuing to burn at Auckland's SkyCity convention centre.
A video shared to Twitter by an Auckland local reveals the bright orange flames continuing to rage on the roof of the $700 million centre - more than seven hours after the blaze began.
Fire and Emergency (FENZ) public information manager, Thomas Harre, told Newshub that although the fire is fully contained, it's proving difficult to fight.
- As it happened: One person unaccounted for as emergency services 'at capacity' to contain blaze
- Person taken to hospital in serious condition confirmed to be firefighter
"It's under the roof and on the roof... it's in a very difficult place at the construction site, as it's semi-built it adds to the complexities of firefighting," said Harre.
"We'll remain present on site well into the night and early morning to monitor it."
FENZ assistant area commander Dave Woon told reporters on Tuesday afternoon that the fire was proving "very challenging" to extinguish.
"It is a large fire involving gas cylinders. It started around the roof, around the guttering area. There is bitumen [asphalt] and insulation on fire... about two layers of insulation which appears to be straw," he explained to reporters.
- Live updates: Huge fire breaks out at SkyCity convention centre
- Watch: Dramatic footage shows smoke billowing across Auckland city
- SkyCity convention centre fire: Photos and videos
- 'It was hot against the windows': Witness in nearby building on SkyCity fire
"It's a very challenging fire, we've been here for hours and we're not on top of it... but with the resources that have arrived, we should be able to make progress."
Firefighters are working to defending neighbouring buildings from the blaze.
St John Ambulance confirmed earlier that three people have been treated at the scene for minor injuries. A firefighter battling the blaze was rushed to Auckland Hospital following an unrelated medical event.
Following an evacuation of SkyCity, hotel guests have allegedly been moved to the Crowne Plaza.
The official cause of the fire is still unknown, although it's suspected an unattended blow torch at the construction site is to blame.