Thames Valley Police is warning Aylesbury Vale residents to be vigilant following a number of distraction thefts.
The three thefts have happened in shop and garden centre car parks in Aylesbury and Wendover.
The victims have unloaded their shopping into their vehicles and put their handbags on a seat.
At this point they have been distracted by someone asking for directions, saying there is a defect with their vehicle or asking something about the trolleys.
Whilst they are talking with this person an accomplice has stolen items from inside the car, such as bank cards or purses.
During one of the incidents, money was subsequently withdrawn from a cash point at the store.
The offenders have been reported to be white and believed to be of Northern European or Mediterranean European/Hispanic descent.
The police are urging people to be on their guard when returning their trolleys or putting valuables into their vehicles, and to not become distracted by strangers talking to them.
They say to take care when putting PIN numbers into the card device and making sure nobody can see what is being entered.
If you see people in the car park acting suspiciously call the police immediately, trying to remember what they look like, a clothing description, how many there are and whether they are men or women etc.
To report any suspicious incidents contact the 24 hour police enquiry centre on 101 or if you suspect a crime is in progress dial 999.