Residents of Merthyr Tydfil and surrounding areas are being urged to be on their guard after a spate of gas meter thefts in the town.
People are being left without hot water and heating by criminals who police suspect have been stealing the meters for scrap or to sell on.
Thieves have struck in five different places throughout Merthyr in the last 10 days.
Incidents have been reported in High Street, Alexandra Road, Holly Way, Cyfarthfa Mews, and Penderyn Close.
An identical theft has also been reported in Aberdare.
The meters are being recklessly ripped from outside homes, leaving pipes dangerously exposed, and homeowners and others nearby at risk.
Officers are linking the incidents and are warning residents to expect criminals to look for other opportunities to strike again.
They are appealing for information that will help them make arrests and prevent further incidents.
Anyone who may have seen people acting suspiciously, or who has information about who is responsible, is urged to contact South Wales Police’s non emergency 101 number or call Crimestoppers anonymously on 0800 555 111.