Five people have been injured, four seriously, in an explosion in central Auckland.
Fire and Emergency New Zealand (FENZ) told Newshub crews responded to reports of the explosion just before 6:30am.
Police said officers assisted FENZ with the incident on Halsey St.
St John initially told Newshub one person was critically injured but their condition has since been downgraded to moderate.
The four other people injured are in serious condition.
Ten ambulances responded to the explosion, including two rapid response units, St John said.
AM understands the explosion happened in a Portacom at a construction site on Auckland's viaduct.
It's understood it was caused by "a mini BBQ or heating device or gas cooker... that a group of construction workers were heating up and going to have breakfast together before their shift started", reporter Natasha Payne said.
"Work hadn't started yet, they were going to have some kai together and that's what set off the explosion," said Payne, speaking from the scene.
"I talked to a witness before who started work at 6:20am... She said she was just preparing for the day and then smelt some smoke and came outside, and that's when she heard and saw some police and ambulance come down as well."
Payne described the aftermath of the explosion.
"As you can see behind me you can see some clothes, some gumboots, which are quite charred," she said. "They were taken off some of the people who were injured."
A nearby worker told Newshub they could see three to four police cars on the scene as well as multiple firetrucks and ambulances.
The worker said they could see at least two people being attended to.
Pakenham St West was closed with police officers diverting people from the scene.
All those injured were taken to Middlemore Hospital, St John said.
On Friday evening Middlemore Hospital told Newshub, two patients are in critical but stable conditions and three are in a stable condition.
