Tools worth around £1,500 were stolen from a works van in Kirkpatrick Durham last week.
The vehicle was broken into while it was parked in Church Road.
The theft took place sometime overnight between Thursday and Friday.
Drills, a circular saw, a radio and a crimping gun were among the items taken in the raid.
The incident is one of five similar hits on works vans reported to police in recent days.
Constable Ruairidh Matthews said:“We would urge those who carry tools in their vehicles to think very carefully about where they park.
“Vehicles should be locked and secured at all times when parked up.”
Anyone who sees a crime in progress should phone 999 or 101 to report suspicious behaviour.