Arsonists tried to torch a trailer carrying a chemical toilet in an incident at a campsite near Otley.
They put a hessian cover underneath the trailer at Oakwood Events Campsite in Newall-with-Clifton before setting fire to it on Friday night. Police said it caused extensive damageto the underside and front of the trailer.
PC Marie Scott, of North Yorkshire Police, said: “This was potentially a very dangerous act, as there were gas bottles and a bin store nearby.
“We are working closely with the fire service to try and trace the offenders and I urge you to get in touch if you have any information that can help the investigation.”
Call North Yorkshire Police on 101.