ORANGE, Calif. (AP) — Authorities say two Southern California call centers that facilitated illegal drug deliveries distributed at least $2 million worth of heroin.

A federal grand jury has indicted 19 people in connection with the scheme, charging them with offenses tied to narcotics and money laundering. Twelve of them are expected to be arraigned in federal court in Santa Ana on Tuesday.

It was not immediately clear if they had attorneys who could speak on their behalf.

The remaining seven are being sought.

Authorities say the suspects operated a heroin ring between March 2017 and this April in Orange County by obtaining the drugs from suppliers in the U.S. and Mexico.