Firefighters responded to a factory fire in Aylward Avenue, Thomastown at 1:47pm after multiple calls to triple zero.
Arriving on scene within three minutes, firefighters observed smoke issuing from the factory and workers evacuating.
The response was escalated to a second alarm.
Fire Rescue Victoria (FRV) firefighters, wearing breathing apparatus (BA), began searching for the seat of the fire.
The fire was located in a conveyor machine deep inside the factory. Crews working to isolate the machine and extinguish the fire.
All workers evacuated safely and were assessed by ambulance officers.
The fire was deemed under control by 2:26pm.
Firefighters then commenced ventilation of the heavily smoke-logged factory.
The cause of the fire is not yet known and will be investigated by FRV fire investigators.
Firefighters remain on the scene.
