Toronto police have issued a warning about a fraud and extortion scam in the GTA that involves threatening phone calls or text messages from U.S. phone numbers.

In a public safety notice on Monday, police said the text messages contain “graphic violent images,” but they did not elaborate.

The calls and texts are from American phone numbers with the area codes of 470 and 404, police said. Both area codes are found in U.S. state of Georgia.

Police said the scam is being reported with increasing frequency in the Greater Toronto Area.

According to police, the calls and texts include a demand for money, and if the amount is not paid, the sender alleges that violence will follow.

“We would like to advise the public that this is a known scam in a bid to extort money from the receiver,” police said in the release.

Police said residents should do the following to avoid becoming a victim of fraud:

• Be aware of the fraud scam.

• If you receive one of these messages or phone calls, report the incident to police immediately.

• Do not pay any money.

• If your information has been compromised in a data breach previously, change passwords to your accounts.