Large fire in Wellington CBD contained

Workers returning to their offices after the fire. Photo / Solbin Kang

Hundreds of people were evacuated from central Wellington office towers after a fire sparked by workmen on a roof sent thick smoke billowing through the capital.

The fire at Pastoral House on The Terrace also brought traffic to a standstill as multiple fire crews rushed to the scene.

Emergency services received multiple calls about the fire from about 10.25am.

The scene of the fire. Photo / Lucy Bennett

Fire Service area commander David Key said the fire was on the 14th floor roof of Pastoral House, which houses the Ministry for Primary Industries.

Should I move the oxygen away from the smoke? #wellington pic.twitter.com/Hv1fpTsRDw

— gillian_clark (@gillian_clark) November 4, 2015

"Workmen were gas axing out an old water tank, or something like that, which caught fire," Mr Key said.

Emergency services are at the scene. Photo / Amy Carnie

"The fire has been put out and the subsequent alarms are basically from the buildings either side where the smoke from the initial fire has drifted into the air conditioning system, gone through the building and set off smoke detectors."

Three buildings were evacuated - Pastoral House, The Treasury building, and Prime Property Tower on Lambton Quay, whose tenants include broadcaster TVNZ.

The Treasury and TVNZ buildings are among properties on The Terrace and Lambton Quay that have been evacuated. Photo / Supplied

Mr Key said office workers were now being allowed back into their buildings.

"The fire is now out, contained where it started."

A witness at the scene said thick smoke was seen billowing down The Terrace. The road was blocked for some time, with traffic building up.

Treasury employee Kirsten Jensen said she had seen lots of smoke on top of Prime Property Tower.

"I could see black smoke coming from the top of the building," she said.

"We were evacuated soon after that."