Firefighters and police have joined forces to investigate a spate of arsons in the Skeffington Road area of Ribbleton, Preston.
At 10.15pm on Sunday, fire crews were called to a car on fire near garages on the road.
Officers were unable to save the car from being destroyed and said the cause was likely to be deliberate.
Preston Watch Manager Mark Woodward said: “It’s the forth time in a week we’ve been called to an arson attack on a car in the Skeffington Road area.
“To stop this happening again, we’ll be taking a multi-agency approach with the police and reviewing things like CCTV.
“Whoever is doing this is putting lives at risk by setting cars on fire and also tying up valuable fire resources.”
Nobody is believed to have been hurt in any of the fires.
Anyone with information on the fires is asked to contact police on 101 or Crimestoppers on 0800 555111.