The United States has charged leaders of the Mexico-based Sinaloa Cartel with running a fentanyl trafficking operation fueled by Chinese chemical and pharmaceutical companies, U.S. Attorney General Merrick Garland said on Friday.

Three sons of Joaquin "El Chapo" Guzman, the onetime leader of the Sinaloa Cartel now imprisoned in the United States, were among those charged, Garland said.

Ovidio Guzman Lopez, one of his sons, was arrested in Mexico and is awaiting extradition proceedings, federal prosecutors in Manhattan said.

"They know that they're poisoning and killing Americans. They just don't care because they make billions of dollars doing it," Anne Milgram, chief of the U.S. Drug Enforcement Administration, said of Guzman's sons. "Their greed is shocking and without bounds."

Prosecutors also charged four owners of Chinese companies that allegedly provided precursor chemicals to the cartel.

The U.S. Treasury Department on Friday also slapped sanctions on China-based chemical companies Wuhan Shuokang Biological Technology Co Ltd and Suzhou Xiaoli Pharmatech Co Ltd.

(Reporting by Katharine Jackson in Washington and Luc Cohen in New York; editing by Jonathan Oatis)