Two people have been injured after an explosion rocked an apartment building in central Wellington this afternoon.

Emergency services are in attendance at an incident in Church St after receiving reports of a fire in a building shortly before 1pm.

Wellington Free Ambulance said it sent three ambulances to the scene and two cars.

Two people have been taken to Wellington Hospital, one person has serious injuries and another person has moderate injuries.

Roadblocks are in place on Boulcott St and motorists are advised to avoid the area and expect delays.

Fire and Emergency (Fenz) said they are in attendance at an incident on Church Street in central Wellington this afternoon.

Crews were alerted to an alarm activation at an apartment building around 1pm. Upon arrival crews were able to ascertain there had been an explosion, Fenz confirmed.

There are 11 crew in attendance and all residents have been evacuated from the building.

Fire and emergency are attending the fire on Church St in central Wellington. Photo / RNZ, Kate Green 

Apartments in the building are leased to Kāinga Ora from the Kirva Trust- a charitable trust set up by Maurice and Kaye Clarke to provide housing and support to those in Wellington most in need.

Kāinga Ora Greater Wellington Regional Director Vicki McLaren said they were concerned to learn about reports of an explosion at one of the agency’s Church Street flats.

“Our immediate priority is checking on the safety and wellbeing of our customers and we have staff onsite who are ready to offer support once we can access the building or reach the customers by phone.

“The cause of the incident is a matter for Fire and Emergency New Zealand to investigate, but we will provide any assistance we can as a landlord.”

Police and fire trucks at the scene in Church St in Wellington's CBD. Photo / Jamie Clumpas 

Boulcott Street is closed, and the public are being asked to avoid the area.

Victoria University Katharine Jermyn Hall resident Darcy Lawrey said she saw emergency services heading down Boulcott St at about 1pm and went to the scene to see what was going on.

“We have seen some people being taken into ambulances wearing what looked like fire-proof blankets. There is a lot of water on the road.”

“There were police cordons at both ends of Boulcott St and a very heavy police presence. A lot of hazmat units and it looks like a pretty active situation,” Lawrey said.

Another witness said they saw unmarked police cars outside the apartment building yesterday.

“A bunch of cops all went in the building and came out and arrested about three people,” they said.

A nearby resident said: “At 1pm there was the fire alarm that went off. We’ve always heard them go off.”

“We went to the window and we looked out and saw heaps of police, then we saw a guy come out with a blanket over his head walking down the street.

“We talked to some neighbours and they said they heard an explosion and heard him screaming.”