Lincolnshire Police are investigating more than 20 cases of metal thefts, after copper pipes were stolen from city homes at the weekend.
The majority of these crimes took place over the weekend in Limeberry Place and Appleby Way in Lincoln.
Criminals cut the copper central heating outlet pipes from the outside of around 10 houses in each road. A number of houses in neighbouring streets were also affected.
Police are urging residents to be vigilant and to report any suspicious activity on their roads immediately.
Good descriptions of suspects and car registration details are extremely useful.
Officers are also appealing for anyone with any information to get in touch with them and help them with their enquiries.
Scrap dealers are being reminded that anyone handling this metal is committing a criminal offence and will be prosecuted.
Call Lincolnshire Police with information on 101, or call independent charity Crimestoppers anonymously on 0800 555 111.