Landlords in Lincolnshire whose properties are empty are being warned they could be targeted by copper thieves.
Lincolnshire Police has urged property owners to invest in extra security.
The warning comes following an increase in thefts of boilers and pipes from empty properties and those under renovation.
Unoccupied houses in Swift Gardens and Browning Drive in Lincoln have recently been targeted, police said.
Residents living near empty properties are also being asked to be vigilant and to report suspicious activity to Lincolnshire Police.