Homes were evacuated today as firefighters battled blazes at two tyre depots in Dungannon, Co Tyrone.
Up to 60 crew members were sent to the burning buildings at Scotch Street and Ballygawley Road in the town.
Fire and Rescue Service Group Commander John Allen said flames and poisonous smoke were belching into the air, while a cylinder present at one location heightened fears of a possible explosion.
"Apart from the obvious of persons getting burnt, the biggest problem is the thick black toxic smoke which is being released into the atmosphere," Mr Allen said.
"As a result we have evacuated a number of people from their homes in order to protect their well-being."
The fire authority was alerted by passers-by, including a lorry driver, just before 5 a.m.
The depots, which store large quantities of tyres, both suffered significant damage. Once the blaze is extinguished investigators will launch a probe to discover the cause of the fire.
Although no-one was injured, the explosion risk meant those forced to get out of surrounding houses faced a possible 24-hour wait before being allowed back.
PA