Firefighting efforts have been successful in reducing a significant fire at a scrap yard in Woolston, Christchurch, says Assistant Commander Dave Berry.

Fire and Emergency was alerted to cars on fire at the scrap metal yard in Woolston, at 7.58pm on Wednesday, This was escalated to a fourth alarm fire by 9.01pm.

At its peak 18 fire trucks were used to fight the blaze with more than 50 firefighters on the scene.

Dave Berry says the fire has been contained to the main car pile, although it is still burning and will be for some time.

"There are six fire trucks and 30 firefighters fighting the blaze at the moment. Diggers have arrived on scene and will be pulling the pile apart to aid in the dampening down of this fire.

"This will be a long duration incident and firefighters are expected to be on the scene throughout Thursday.

"We do still encourage residents and businesses in the immediate area to keep their doors and windows closed, and for people to stay indoors in case of flare ups and smoke issues.

"Cordons remain in place on the streets around the fire, including Cumnor Terrace, Garlands Road and Marshall Street.

"We again would like to thank the public and surrounding businesses for their co-operation as we fight this fire.

"Environmental efforts continue to ensure the runoff into the Heathcote River is either stopped or contained. Booms were put in place on the river and sucker trucks are being used to drain any runoff."

© Scoop Media