Fire crews are battling a large blaze at a cinema in the Auckland suburb of Botany Downs.

Fire and Emergency New Zealand said the fire started in an air-conditioning unit on the roof of the three-storey building attached to the shopping mall at Botany Downs.

Fenz said crews were fighting the fire from both inside and outside the building.

A worker at the Botany Town Centre said flames were shooting out of the Hoyts movie theatre.

She said about 100 people were standing outside the mall and officials were telling people move away.

The worker said it was a “shocking sight”.

Fenz said traffic in the area may be affected by road closures and diversions.

A resident who lives in the area said police had blocked off part of Chapel Rd.

Fenz has classified the fire as a third alarm, which means fire trucks from around the Auckland region were being called in to help.