Truck drivers in Gloucestershire are being warned to be aware of fuel thieves after several incidents of diesel being siphoned out of vehicles.
Drivers are being told to be particularly wary when leaving their cabs unoccupied or parked up in lay-bys.
Two incidents have been reported in the Cotswolds and a third in Stonehouse.
In the first, which took place at around 11pm on 10 June while a lorry was parked in a lay-by on the A417 near Elkstone, the offenders approached the vehicle while the driver was sleeping before siphoning out an unknown amount of diesel.
The second incident in the Cotswolds was reported on 16 June while a lorry was parked at Gloucester Beeches.
It is believed the offenders siphoned the diesel out at some time between 10pm and 2.45am before leaving in an unknown vehicle.
The third incident was reported at a trading estate in Stonehouse on 21 June after a driver noticed unknown offenders had unlocked the diesel cap before starting to siphon fuel. It is believed they were disturbed before leaving in what is thought to have been a yellow van.
Anyone with further information is asked to contact Gloucestershire Police.