DOZENS of firefighters were called out when 29 cars at a scrapyard were set on fire.
Four fire engines were called to the blaze which was started overnight at Goosehouse Lane in Darwen.
A joint police and fire investigation has now been launched after the alarm was raised in the early hours of Friday morning.
Firefighters said thick smoke covered the area and the flames could be seen for some distance just before 1am.
Firefighters had to tackle the blaze for several hours using three jets.
Watch manager Stephen Brown at Darwen Fire Station said the fire was being treated as suspicious however it was not yet clear whether the flames spread from one car, or whether multiple fires were started.
He said: “It was a large fire where the smoke and flames were very visible from some distance away. It became clear it was a fire involving multiple cars at a scrap yard on the lane. It is being treated as suspicious.
“Possibly the fire spread from one car to another. It has seen approximately three vehicles gutted by flames.”
Firefighters tackled the blaze for around two and a half hours and prevented further damage taking place on the business premises.
The blaze was stopped before fire spread to another 30 cars which were also on the site and which remained undamaged.
Fire investigators from Lancashire Fire and Rescue service were at the scene yesterday and the incident is also being investigated by Lancashire Police.