Copper piping, gardening tools and car batteries have been stolen during a string of break-ins in Ross-shire and the Black Isle this week.
Officers are now investigating whether the six incidents, which were reported on Thursday, are linked.
In one incident at the Dingwall Recycling centre, car batteries removed from the premises.
Building contractors in Alness and Evanton have also reported copper piping stolen following damage to security fences and containers.
On the Black Isle, padlocks were damaged at a residential property in Rosemarkie but no items are thought to have been removed.
In Balblair, gardening tools were removed from an insecure vehicle and electrical items from within a shed were also taken at a separate address.
Inspector Nick MacRae said: “It’s disappointing to hear of these incidents taking place within a short space of time. Inquiries are ongoing to establish whether the incidents are linked so officers would greatly appreciate hearing from anyone who may have information to assist with the investigation.
“Although Ross-shire and the Highlands in general is a very safe place to live, unfortunately rural properties and businesses can be seen as an easy target to those intent on committing crimes in our local communities.
“We would urge local residents to take extra care to secure property and vehicles, including outbuildings and sheds. Keeping valuables away from view where possible and installing security lighting can also deter opportunistic thieves.”