Heartless thieves have targeted pensioners in three Feltham homes, making off with cash, handbags and jewellery.
Two victims, aged 59 and 88, were distracted by a woman asking for paper to write a note before her male accomplice stole cash and a gold ring from their Hayling Road home, on May 29.
The same day, in Fernside Avenue, two male thieves robbed a couple, aged 98 and 78, of a handbag by posing as water board representatives searching for a stopcock.
And on Saturday, an 85-year-old woman, in Barnlea Close, was distracted by a woman pretending to deliver a parcel while a man took her handbag.
Det Insp Paul Beetham, of Hounslow Crime Squad, said: "Please, please do not let people into your house who you do not know or who cannot prove who they are. We have recently had an increase in burglaries where people have tricked their way into the houses of the elderly or less able.
"People committing these offences are beneath our contempt but they are also devious and determined, we are putting great efforts into trying to bring them to justice please help us to do so."
Anyone with information about any of the crimes above should call Hounslow CID on 020 8247 6160 or Crimestoppers anonymously on 0800 555 111.