The FBI is looking for two women it says come from Mexico to Tucson to perform unlicensed medical procedures to make butts bigger.

The women — Ivonne Clarisa Ceballos Tapia and Guadalupe Rubio Prada — are named in an FBI news release today that warns the pair are performing cosmetic medical procedures "which enlarge the buttocks area via injections of a non-approved FDA substance."

The women are not licensed and are injecting polyacrylamide hydrogel (PAAH) into women. PAAH, a watery gel, is banned in the United States, Special Agent Perryn T. Collier said in a news release.

The FBI and the state Attorney General's Office are working to identify women who might have received the procedure. Anyone treated by the women is asked to seek medical attention.

Anyone with information about the probe is asked to call the FBI at (520) 623-4306 or Assistant Attorney General Mike Jette at (520) 628-6504.