A series of robberies on two teenage girls, a woman and an elderly man are being linked by detectives.
Thames Valley Police are searching for a man described by each victim as black and travelling in a dark-coloured saloon-style car.
The crimes took place over a two-hour period from around 6am to 7.50am on Saturday in the Ascot, Datchet, Windsor and Old Windsor areas of Berkshire.
The first involved a 71-year-old man in Ascot who was confronted by a man who jumped out of a car and demanded he hand over his wallet. The victim refused and ran off.
In the second robbery, a 17-year-old girl was walking in Old Windsor at 6.50am, when a man got out of a car and demanded her mobile phone. The girl refused and the man snatched her handbag from her.
The third robbery took place in Datchet and saw a 15-year-old girl threatened, a police spokesman said. She had her handbag stolen by a man who left in a dark-coloured car.
In the final robbery, in Windsor, a woman was walking along the road when a car pulled up. A man approached her and stole her handbag before getting back into the car.
Detective Sergeant Jonathan Groenen said: "We believe that these incidents are linked and I would urge anyone with information about any of these robberies to come forward."
Anyone with information is asked to call Thames Valley Police on 101, or Crimestoppers on 0800 555 111.
