There has been a spike in thefts from vehicles in Caerphilly town and the Aber Valley, Gwent Police has said.
The police have issued a warning to motorists, particularly van drivers, to keep an eye out and report any suspicious activity.
Incidents have been reported near Corbett’s Lane, Churchill Park and the Aber Valley.
PC Stuart Lewis said: “We are currently investigating each reported crime and asking residents to lock their vehicles at all times.
“We’ve seen that Ford Transits carrying work tools have been particularly targeted.
“During our early enquiries, there has been no signs of forced entry, so there is a strong possibility that some sort of device or skeleton keys are being used by the offenders.
“Where possible, I would advise van owners to remove expensive tools from their vehicles at the end of each day.”
PC Lewis added: “It’s also a good idea to property mark your tools and equipment, so that if they are recovered they can be traced back to you.
“Following these recent thefts, I would encourage van owners to be particularly vigilant. If anyone sees anything suspicious in their area, then please get in contact with us.”
Anyone with information can contact Gwent Police on 101.