SAN FRANCISCO (AP) — Apple is warning consumers about scam artists who pressure their victims into transferring money by purchasing iTunes gift cards after the fraudsters spin a bogus story about unpaid bills or a relative who needs bailing out of jail.

Authorities have previously warned about similar scams involving pre-paid debit cards. But in recent weeks, the IRS and the Federal Trade Commission have said criminals are using the popular Apple gift cards as an easy and difficult-to-trace method of transferring cash.

Apple posted a warning on its website Friday, advising that iTunes cards should only be used for online purchases of digital music, books or apps, and not for transferring money. Apple also said it's advising retailers to be alert for people buying them in large quantities.