The U.S. Treasury Department has imposed sanctions on more than a dozen Mexican companies and four people it says worked with a powerful drug trafficking cartel to scam elderly Americans in a multimillion-dollar timeshare fraud.

The 13 businesses are accused of working with the Jalisco New Generation Cartel, a group designated by the U.S. government as a foreign terrorist organization.

The FBI says the Jalisco cartel began operating in the timeshare industry in 2012, running call centers in Mexico where employees impersonated U.S. brokers, attorneys and sales representatives to defraud property owners.