Thousands of pounds worth of power tools have been stolen during a spate of van break-ins across the Vale over the festive holidays.
Detectives say at least ten thefts have been reported in the last three weeks, mainly in the Penarth and Barry areas at night.
South Wales Police are urging vehicle owners to be vigilant while their investigation continues.
A force spokesperson said: "Thieves steal power tools and often attempt to sell them on, with no regard for the livelihood of those they have stolen from."
"Please be vigilant to this kind of crime. While enquiries continue to identify those responsible, please take extra precautions to protect your property and report any suspicious activity."
Anyone with information about the thefts should contact South Wales Police on 101 and via the live web chat or Crimestoppers anonymously on 0800 555 111.

Post Office Seeks New Operator in Dinas Powys as Village Faces Loss of Its Last Branch
Gardening team praised after helping police clear fallen tree near St Brides Major
Specsavers calls on children in Barry to design Wales Deaf Rugby World Cup shirts
Whitmore High Named One of UK’s Best Workplaces for Development
Steel Signing Marks Major Milestone in St Richard Gwyn School Redevelopment
Two Rescues in Record Heat as Volunteer Teams Respond to Afternoon Emergencies
Police find evidence of a large-scale cannabis cultivation at Riverside Place property fire
Network Rail confirm closure of Brookside level crossing in Dinas Powys
Police given powers to ask people to leave Comeston Lakes Country Park
Planned children’s role play centre could be given the go-ahead by Vale Council
Marie Curie Garden Fayre deemed huge success
Council seeks views on Future of Colcot Sports Centre and Buttrills Playing Fields
First Minister quizzed on further devolution, budget decisions, and misinformation in FMQs
Extreme heat leads to changes to services and closures
Severe Heat Warning Set to Disrupt Rail Travel Across South Wales This Week
Communities asked to support older people across Wales during severe heat warning
Caribbean Community Wales Brings Wales‑Wide Launch to Barry This Weekend
Community Award winner calls for sanitary bins in men’s toilets after living with prostate‑cancer‑related incontinence
Cardiff Airport Backs Holiday Safety Campaign Honouring Rhoose Teenager Tom Channon