Plumbers and builders have been advised to make sure they remove copper piping from their vans after a spate of metal thefts.
Police believe thieves have been driving around the area targeting vans they believe are carrying copper pipes that come encased in plastic tubes.
Officers have advised people who carry the pipes, which thieves are able to sell on below the market price, should make sure their vans are not tempting to criminals.
A spokesman said: "Our advice to drivers is to remove their piping to a secure location and leave the tubes on their vans open so it’s clear they are empty.
"If the tube is padlocked then that’s an indication to a thief that there is something inside worth stealing."