Police are hunting for firebugs who caused £20,000 worth of damage to two coaches.
The vandals targeted the buses, which are owned by Johnstone-based M&C Coaches, while parked up at an Industrial Estate in Bridge Street, Linwood.
CCTV pictures show three youths breaking into the depot then setting fire to two of the coaches, which were valued at around £10,000 each.
The fire service arrived at the scene around 6.45pm on Saturday, 9th May but were unable to save the vehicles which were well ablaze by the time they arrived.
Johnstone Chief Inspector Simon Wright appealed for any witnesses who may be any to identify the three firebugs.
He said: “We would like to hear from anyone who was in the Bridge Street area of Johnstone between 6.30pm and 6.45pm on Saturday, and may have seen anything which may help us track down the people responsible for the fireraising.”
Anyone with information can call the police on 101.