PHOENIX — Firefighters were battling a large scrapyard fire in south Phoenix late Sunday, sending plumes of dark smoke into the air. 

The fire broke out at the junkyard near 16th Street and Broadway Road around 6:30 p.m. 

About 40 firefighters were on scene. They were able to prevent the fire from spreading throughout the yard. 

No one was injured. 

Phoenix Fire Captain Rob McDade said in an email that it was a "defensive fire." 

The cause of the fire was not immediately known. 

Investigators on scene said the fire was not suspicious and believe spontaneous combustion may have been to blame.

Phoenix junkyard fire
Crews battled a large fire at a junkyard in Phoenix on Sunday, June 6, 2019.
Mike Runyan
Phoenix junkyard fire
Fire crews were battling a junkyard fire in central Phoenix on Sunday, June 9, 2019.
Mike Runyan
Phoenix junkyard fire
Fire crews were battling a junkyard fire in central Phoenix on Sunday, June 9, 2019.
Mike Runyan

More updates to come from 12 News.