The IRS warned people on Thursday not to fall for the latest telephone scam in which people pretending to be from the IRS or a tax collection agency demand payment of a federal "student tax."

The warning comes as parents across the country prepare their kids to go back to school.

"People should be on the lookout for IRS impersonators calling students and demanding that they wire money immediately to pay a fake 'federal student tax,'" the IRS said. "If the person does not comply, the scammer becomes aggressive and threatens to report the student to the police to be arrested."

"Although variations of the IRS impersonation scam continue year-round, they tend to peak when scammers find prime opportunities to strike," said IRS Commissioner John Koskinen. "As students and parents enter the new school year, they should remain alert to bogus calls, including those demanding fake tax payments from students."

The IRS said scammers have been known to try to impersonate the IRS or local police, and may even threaten an arrest if a payment isn't made over the phone. But the IRS said it will never demand payment by phone, and most often mails tax bills to people.

It said the agency will never "demand that you pay taxes without giving you the opportunity to question or appeal the amount they say you owe."