Homes were evacuated when a row of garages was torched in South Normanton on Sunday.
Three crews from Alfreton and one from Crich were called to Brickyard Lane at 3pm and cordoned off the area after it was established that acetylene cylinders were stored in one of the garages
One mainline and two monitors were used to extinguish the blaze. The electricity board attended as a precaution because of a nearby substation.
Five homes were evacuated. Police are treating the incident as arson. Call police on 101 or Crimestoppers anonymously on 0800 555 111.