Police are warning elderly people to be vigilant after two burglaries by bogus callers in Maidenhead.
Three men claiming to be "from the water board" called at two different houses in the Berkshire town, saying they had to check for a burst pipe.
They ransacked bedrooms in both homes and stole an amount of cash.
Thames Valley police stress there is no such thing as "the water board" and say genuine callers would identify the company for which they work.
Officers were called at 1900 GMT on Friday to the house of an elderly couple in Boyn Hill Road, and shortly afterwards to a similar incident in Clare Road.
The robbers were white, wearing navy blue trousers and jogging tops with a green and yellow emblem on the left breast.
Each wore a blue baseball cap with the same emblem on the front.