Internet users have been warned to be wary of e-mails asking them to confirm details of their accounts, following a scam in Co Tyrone.
Police said fraudsters claiming to be from a major Internet service provider targeted a number of people in the Clougher area.
Those behind the scam sent e-mails giving a deadline to respond with user names and passwords or risk losing e-mail accounts.
A police spokesman said: "We are still trying to establish how the fraudsters got e-mail addresses in the first place, but that was only their first step.
"We believe that the crooks then used information from those who responded to collate names and e-mail addresses.
"Some people then received a message from someone on their contacts list claiming to be stranded without money in England and asking for money to be transferred electronically to a bank account."
Police have said they do not know how many people received the message and that, so far, they have not been contacted by anyone who sent money on.
The scam was carried out two or three weeks ago.
While the initial report came from the South Tyrone area, police believe that a number of people north and south of the border have been contacted by the fraudsters.
The spokesman added: "We are advising all internet users to be wary about messages they receive. Anyone who has received a similar message is asked to contact their local PSNI or Garda station."
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