Acting U.S. Attorney Larry Brown said at a news conference in Sacramento this morning that federal drug enforcement agents have seized about 50 kilograms of heroin worth about $4.4 million.
Heroin imported by the trafficking operation was sold in cities including San Francisco, East Palo Alto and Oakland.
The suspects were believed to be transporting the heroin from Michoacan, Mexico, to Southern California, through the Central Valley and up to the Bay Area, Brown said.
The 18-month investigation, called "City Commuter," was carried out jointly by the Drug Enforcement Administration, the San Francisco Police Department and the San Mateo County Narcotics Task Force.
In addition to the 50 kilograms of heroin, about $250,000 in cash allegedly destined for Mexico was seized, Brown said.
Ten of the suspects have been taken into custody or were already in custody on unrelated charges when the indictment was unsealed earlier this week, Brown said.