Los Angeles-based City News Service says Wednesday's arrests targeted members and associates of LA's Grape Street Crips. Authorities say they seized about 100 gallons of PCP and the chemicals used to make it.
Federal prosecutors say the gang distributed the hallucinogenic drug in Texas, Maryland, North Carolina, Oklahoma and New York.
Two federal indictments named 40 people. In addition to the 20 arrests, three people already were in custody and 17 are being sought.