Since the start of last month (October) there have been 67 offences of thefts or attempted thefts from cars in the PE1 postcode area, predominantly in Eastgate, Eastfield, Millfield and Dogsthorpe.
Some of the vehicles have been broken into with windows being smashed, while others have been entered via unlocked doors.
The majority of vehicles have had items stolen, including wallets, mobile phones, laptops, clothing, handbags and cash.
Detective Inspector Justin Howard said: “Last month we put out a public warning and crime prevention advice following the increase in thefts but we are still seeing a lot of offences being reported to us.
“We are working hard to identify those responsible, however I would urge people to double check their vehicles are locked when leaving them unattended and where possible please remove items, particularly those of value such as electronics and money.
“I would also ask anyone who sees suspicious behaviour or notices any potential offenders on home CCTV to get in touch with us.”
Information can be passed to police online or by calling 101. Always dial 999 if a crime is in action.
Advice about how to best protect your vehicles can be found on the force website