Officers are urging residents in North Yorkshire to be vigilant, following a spike in thefts from vehicles across the county.
North Yorkshire Police there had been a sharp rise in the number of vehicles being broken into York and Harrogate over the last month.
Extra patrols are now in place, and local policing teams are organising series of awareness events to encourage residents - especially those working with tools - to mark high value items.
A 30-year-old man has been arrested in connection with the thefts in Harrogate.
Inspector Lee Pointon, of York Neighbourhood Policing Team, said: “We urge tradespeople with vans containing high value tools to come to one of our property marking events. We have recently seen a rise in tradesperson’s vans being targeted in York and we want to do all we can to help you keep your property secure.
“Often, there is no way of identifying rightful owners of stolen property. Being able to trace the ownership of the property not only helps people get their property back, but it can also provide evidence that is vital in securing convictions.
“Pop down to one of our free events to have your property marked by our Dot Peen Machine and receive advice on replacement locks and other security devices”.
The next police property marking event will be held in the B&Q car park, Skipton Road, Harrogate, from 9am on Saturday.
In York, a similar event will take place from 4.30pm on Tuesday at Athena House, in Kettlestring Lane.