A motor home was set on fire in Liversedge in what firefighters believe was a deliberate attack.
Crews from Cleckheaton and Batley were called to the incident on Ings Road at 2.50am this morning (Thursday).
The motor home was completely alight when they arrived and they used one breathing apparatus and two hose reels to extinguish it.
Nobody was in the motor home.
The cause of the fire is under investigation but a West Yorkshire Fire Service spokesperson said it is being treated as suspicious.
Fire crews left after about 40 minutes.