Thames Valley Police is appealing for information after a series of burglaries in Banbury and Bicester.
Members of the public are urged to make sure their homes are secure, and valuables are locked away or kept safe after the break-ins, which police believe have been carried out by the same group.
Residents are also being urged to report suspicious callers, people and vehicles to police.
While most of the recent break-ins have been in Banbury, several have been reported in Bicester over recent weeks.
Det Con Mark Personius, of Banbury Police Station, said: “Cherwell police area is a very safe place to live and house burglaries have been reducing over recent years.
“I wanted to make the public aware so that precautions can be taken, individual security can be improved and for the community to be our eyes and ears and report suspicious incidents to police.
“If you have any information on any of the offences or witness anything suspicious please contact police.”
The first Bicester incident took place on Thursday, July 18, at 10.25am on Goodwood Road, when a burglar got into a home by forcing open a rear window.
Jewellery and medication were stolen.
On Tuesday, July 23, between 1pm and 5.10pm in Leach Road, thieves forced entry to a home through a rear door.
The home was searched and a quantity of Asian jewellery was stolen.
On Saturday, July 27, at 7.55pm in Ravencroft, Langford Village, thieves forced their way into a home through the front door before being disturbed by the homeowner.
The group of four white men were described as being aged in their early 20s. They drove away from the house in a black Volkswagen Passat, around two to three years old.
On Saturday, August 3, at 4.45pm in Queens Court, burglars broke into a home, activating the burglar alarm, before fleeing with a haul of Asian jewellery.
The series of burglaries is believed to have started in mid-July.
More than 10 other Banbury burglaries are believed to have been carried out by the same group.
The gang appears to be targeting Asian jewellery, but footwear, perfume, cash and foreign currency have also been taken.
A Mercedes car was also stolen in one burglary after keys were taken.
Anyone with information should contact Det Con Personius from Banbury police station via the Thames Valley Police enquiry centre on 101.
Details can also be passed to Crimestoppers on 0800 555111.