Three houses have been ransacked and money and jewellery stolen in Derry.
Detectives believe the burglaries, on Thursday, January 11, may have been linked despite having taken place right across the city.
Appealing for witnesses police also warned householders to be wary of potential rogue traders who "may attempt trick their way into your house to commit a burglary".
Detective Constable Brennan said: “We believe these three incidents may be linked. In the first, entry was forced to the rear of a property in the Messines Park area between 6pm and 6.45pm.
“The house was ransacked and items of jewellery taken. No-one was in the house at the time.
“The second burglary was reported at around 7.20pm in the Glenmore Park area of Altnagelvin.
"We believe that sometime between 3pm and 7pm, entry was forced to the rear of a property and it was ransacked.
"Again, no-one was in the house at the time. A sum of cash was stolen along with a number of personal items including a watch.
“A third burglary, in the Woodbrook area of the city was reported at around 7.45pm. A sum of cash was stolen along with a quantity of jewellery.
“I would also advise everyone to be aware of cold callers at your door. Most will be genuine but some could be trying to gain access to look around your property.
“Not all are rogue traders – but some are. Unofficial traders can overcharge unsuspecting and often older householders for poor quality work or work that is never completed at all.
"Others may try to sell shoddy or over-priced goods, or attempt to trick their way into your house to commit a burglary.
“Report any activity that raises your suspicions to police immediately.
"This is a good way to alert us so we can investigate - and will help deter criminals and reduce crime in your area.
“We are appealing for anyone who saw any suspicious activity in these areas around the specified times, or anyone with any information that could assist with our investigation, to contact detectives in Strand Road on 101 quoting reference 1140 of 11/1/18.
“Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.”