A fire at a Somerset tyre factory is believed to have been started deliberately, the fire service said.
Fire crews worked through the night to contain the blaze involving 10,000 tyres and 8,000 litres of fuel and oil at Tyre Renewals in Castle Cary.
Devon and Somerset Fire Service said it received nearly 70 calls after explosions were heard at the site at around 14:20 BST on Sunday.
There are no reports of any injuries and the blaze is now under control.
A spokesperson for the fire service, said crews had worked through the night "turning over and damping down" the site.
"Fire investigation officers along with scenes of crime are investigating how the fire started as they believe it to be deliberate," they said.
Onlookers reported hearing a series of bangs at the Torbay Industrial Estate.
At its height, a total of 12 fire engines were involved in the operation.
Residents were told to keep doors and windows closed due to the amount of acrid smoke in the area, which was visible for miles.