Gardaí in Cavan and Monaghan are appealing for people to secure their oil tanks after recent thefts.
Local Gardaí say they've received reports of oil being taken from oil tanks across the region in recent days.
The rising cost of fuel is said to be behind the increase in incidents.
Gardaí say that installing alarms, anti-siphoning devices or security lights can be effective ways to deter thieves.
People are also being asked to be vigilant and to report any suspicious behaviour to their local Garda station.