Officers are appealing for information about a number of incidents along the “Ringway” corridor of Liversedge and Heckmondwike over recent weeks.
PC Chris Birkenshaw from Batley and Spen Neighbourhood Policing Team said: “The most recent attack occurred on Sunday, May 3 at around 4am in the morning at Old Station Court in Heckmondwike in which a caravan was targeted.
“Officers are increasing patrols in the area but we believe that someone out there knows who is responsible.
“We would urge anyone with any information to contact the police to help us stop these attacks before someone is seriously injured or even killed.”
Since then an apparent, but unconfirmed, arson attack on a car took place in Valley Court, Liversedge, at around 5am on May 9.
Anyone who has information should contact PC Birkenshaw on 101 or ring Crimestoppers anonymously on 0800 555 111.