Sussex Police are investigating a series of seven distraction burglaries across West Sussex.
The burglary spree began on May 29, police said, with five break-ins in one day.
Officers received a report of a break-in of a caravan in Havenwood caravan park in Arundel, said police, with two men seen acting suspiciously before leaving in a black vehicle.
Police said four further reports were received later that day - the first at a property in Brookview South in Coldwaltham, near Pulborough, where a safe with identification documents inside was stolen.
There were then reports of men entering properties in Meadsway, Slindon and St James Road, Chichester, pretending to be from a water board company, police said, although nothing was reported as stolen from either.
The fourth break-in was reported at a property in Ferring Lane, Worthing, between 11.45am and 1pm. Items of jewellery and personal documents were reported as stolen, police said.
On the following day, May 30, police said they received a call from a woman in Manor Way in Henfield, reporting three men entering her house while she was in her garden. She reported costume jewellery as having been stolen.
Soon after, another report was received of four men acting suspiciously in the Fairfield Court area in Cowfold and a safe being stolen from a property, said police.
Investigating Officer Detective Constable Jon Berisford said: “We believe all seven of these incidents are linked due to the similarities in circumstances.
“Each of the victims have been left shaken by this experience and support and advice is being provided.
“We are interesting in searching for the owners of a black vehicle with registration X504 UFC which we believe to be linked to each of the incidents.
“If you have information on any of these burglaries or the car in question then we would like to speak with you.
"For our advice on burglary prevention please click here.”
Please report information online or call 101 quoting Operation Tranquil.