A major blaze in Sydney's west has engulfed and severely damaged a factory overnight.
Fire crews reported the fire on Miller Road at Villawood around 1.30 this morning (AEDT), with numerous crews at the scene four hours later.
A statement on the Fire and Rescue NSW website says firefighters contained the blaze around 4.30am and smoke from the factory will be visible well into the day.
It says crews are now monitoring the site are likely to remain on scene for most of the day.
Investigators are trying to work out what sparked the blaze.