THIEVES have stolen hundreds of litres of heating oil and diesel from rural locations near Truro.
Police are warning oil tank owners to increase security in the face of an increase in oil theft.
Officers said heating oil had been taken from St Allen and diesel had gone from machinery in Grampound Road.
Sergeant Chris Manuell, from Truro police, said there had been several incidents reported in St Allen.
"In one report 300 litres was stolen. Particularly vulnerable are oil tanks that are located away from the dwelling and are in rural or isolated places.
"Owners of such tanks should really consider increasing the security so as to reduce the risk of falling victim to this ongoing trend."
Sergeant Manuell said owners of commercial and agricultural vehicles were also vulnerable to attack with a recent report in the Grampound Road area of Truro of up to 100 gallons of road diesel being stolen in one night.
Anyone with any information is asked to contact PC Duckworth by dialling 101 or anonymously via Crimestoppers on 0800 555111.