Bicycle owners in Banbury are being warned to be on their guard after a spate of thefts in the last fortnight.
The majority of the 10 bikes were stolen during daylight hours from outside homes in Neithrop, Grimsbury, Easington and Ruscote.
Thames Valley Police have advised all bike owners to be vigilant and to ensure their bikes are locked up.
They also recommend all bike owners to go to their local police station and have their bikes marked.
"UV pens and cycle coded stickers are always available from Banbury Police Station as well as other police stations in the Area," a police spokesman.