Emergency services responded to a blaze in Bradford city centre on the evening of September 22.
Two fire crews were dispatched to Sackville Street following reports of a vehicle fire, which occurred shortly before midnight.
The crews arrived and successfully brought the flames under control.
However, the fire had already spread to a second vehicle parked nearby, causing damage to it.
Firefighters departed the scene after ensuring the situation was safe, handing responsibility to the police.
West Yorkshire Police confirmed they were alerted to the incident just after midnight on September 23.
Officers attended following a report that a parked van was ablaze on Sackville Street.
The force has indicated that initial evidence suggests the fire was ignited deliberately.
An investigation into the circumstances surrounding the incident remains active, with enquiries continuing.