A fire has broken out inside an electrical substation compound.
Avon Fire and Rescue said three cars were on fire around 20m from the substation equipment, adjacent to Lower Moor Road in Yate, South Gloucestershire.
Nearby roads have been closed, and police have been advising local residents to keep their windows closed.
A fire service spokesperson said three appliances were attending, with four crews working to extinguish the fire, which broke out about 14:30 GMT.