MEXICO CITY (AP) — Prosecutors say inmates at a Mexican prison made extortion phone calls to Mexicans living in several U.S. cities.

Jalisco state prosecutor Eduardo Almaguer said Monday the fraudulent phone calls targeted Mexicans living in Los Angeles, Miami, Chicago and cities in Texas, Oklahoma and Tennessee.

He said inmates pretended to be relatives, a technique used in Mexico in fake kidnap calls. The inmates also managed to get migrants to send them tens of thousands of dollars by posing as lawyers calling from airports, he said.

Both schemes usually involve using a disguised voice to tell people that a relative had been kidnapped or detained and needs help.

A raid at the Puente Grande prison found seven prohibited cellphones, 18 SIMM chips and detailed scripts for the calls.