(MCT) — Local and federal authorities seized $4.6 million worth of alleged synthetic drugs Wednesday in the St. Louis area as part of a nationwide crackdown on synthetic drug manufacturers, wholesalers and retailers.

The drugs seized included suspected synthetic marijuana and stimulants, the latter of which has been compared to a hallucinogenic methamphetamine. The raids were announced Thursday at a news conference hosted by the U.S. Drug Enforcement Administration at its St. Louis offices and attended by law enforcement officials from both sides of the Mississippi River, including Madison County State's Attorney Tom Gibbons, Madison County Sheriff's Lt. T. Mike Dixon and Edwardsville Police Chief James Bedell.