Thames Valley Police took to Facebook to remind residents how important it is to report break-in attempts.
The local police team have received information that offenders have been attempting to gain entry to vehicles in Olney.
They believe people are attempting to use a jamming device for keyless entry vehicles.
Thames Valley Police said: "Unfortunately it doesn't appear all these incidents are being reported.
"Please report incidents to us on 101 or online.
"If you have CCTV footage of suspicious persons in the area, the team would be keen to receive this, please also make contact through the online reporting tool.
"In the meantime please ensure you store vehicle keys safely, ideally in a faraday box or similar."
Further crime prevention advice is available here.
The team will be conducting patrols in the area to provide reassurance and crime prevention.