New Zealand: Several killed in Wellington hostel fire (VIDEO)

At least six people have been killed in a fire that broke out in a hostel in New Zealand's capital Wellington, Prime Minister Chris Hipkins said on Tuesday.

"It is an absolute tragedy," Hipkins said.

New Zealand's head of government said that there were likely to be more than six fatalities. Police have said they expect the death toll will be less than 10.

The cause of the fire is still unclear, police said. 

Firefighters said 52 people had been rescued, some from the roof of the building.

What we know about the fire

The fire broke out on the top floor of the Loafer Lodge in the Wellington suburb of Newtown.

Nick Pratt, an official for Fire and Emergency Services New Zealand (FENZ), said that such fires are rare.

"This is a once-in-a-decade fire for Wellington," he said. "It's the worst nightmare for us."

80 Firefighters and 20 trucks battled the blaze through the night.

Crews remain on the scene of the fire as of Tuesday morning. An FENZ statement said that there was still a risk of roof collapse.

Rescue workers said there are still small fires inside the building and structural and risk assessments are being undertaken.

One of the main roads into Wellington has been closed and traffic is being rerouted.

Australian Prime Minister Anthony Albanese told the media that he spoke to Hipkins and offered assistance. "This is a dreadful human tragedy," he said.