Twelve people were arrested in the Bay Area Tuesday as part of a multi-agency operation targeting an international heroin trafficking ring.

Federal and state investigators served arrest warrants in East Palo Alto, Hayward and Oakland as part of a long-term operation, named "Operation Middle Man", that aimed to dismantle the Santa Clara County-based Carlos Jose Moreno drug trafficking organization -- a large-scale heroin and methamphetamine distributor, according to the state attorney general's office.

U.S. Immigration and Customs Enforcement agents and officers with the Department of Justice-led South Bay Metro Task Force arrested the 12 suspects and seized nine guns and small quantities of marijuana and methamphetamine, attorney general's officials said.

"By combining our resources, authorities and expertise, we've succeeded in dismantling a drug ring suspected of funneling significant quantities of heroin into the Bay Area and onto our streets," said Clark Settles, special agent in charge for ICE's Homeland Securities Investigations in San Francisco.

Law enforcement officials said undercover agents bought more than 3 pounds of heroin during the operation, which began in December 2009.

The attorney general's office said the Moreno organization imported drugs through national and international trafficking sources to be distributed throughout the state and the U.S.

The organization is comprised of Norteno gang members with connections to Mexico and they distribute drugs around San Jose, East Palo Alto, Palo Alto and Redwood City, state officials said.

Law enforcement officials said the crystal methamphetamine was manufactured in California's Central Valley and the heroin was imported from Mexico.

Those arrested today were Palo Alto residents Jose Izabel Moreno, 26; Pearl Moreno, 27; Johnny Chavez, 21; Jose Arreguin, 21; Jose Macias, 25; Elizabeth Kovac, 23; Joventino Lopez-Ortiz, 18; Victor Hernandez, 23; Edgar Enrique Bustos, 18, and Pedro Chavez Chavez, 36, and Daniel Macias, 23, both of Mexico.

The suspects were booked into Santa Clara County Jail and are facing charges that include conspiracy, residential burglary, firearm sales, sale of methamphetamine and heroin and gang enhancements.