Think of it as the West African country of Mauritania's version of "one ring to divide them all."
The FCC has issued an alert to be on the lookout, or in this case "listenout" for "waves" of one-ring, or "wangari" robocalls.
Those are a series of scam calls, often in the middle of the night, that don't give people a chance to answer in hopes that the curious or concerned will call back and rack up per-minute charges on the order of 900 numbers.
The FCC said the calls are using Mauritania's 222 country code and have been "widespread" in New York and Arizona, according to news reports cited by the FCC.
The FCC advises:
"Do not call back numbers you do not recognize, especially those appearing to originate overseas.
"File a complaint with the FCC if you received these calls: www.fcc.gov/complaints
"If you never make international calls, consider talking to your phone company about blocking outbound international calls to prevent accidental toll calls.
"Check your phone bill for charges you don’t recognize."