Law enforcement agencies have arrested more than 2,200 people in an investigation targeting Mexican drug trafficking organizations in the United States, the Justice Department announced Thursday.
The probe, called Project Deliverance, focused on the transportation networks that carry methamphetamine, cocaine, heroin and marijuana into the United States, with return trips of drug proceeds and weapons.
At a news conference Thursday, Attorney General Eric Holder said the extensive operation began nearly two years ago. He said federal agents targeting violent drug cartels have seized nearly 70 tons of marijuana and nearly 1,500 pounds of heroin. Authorities said some of the drugs were hidden inside buses that cross the Southwest border.
But Holder said the fight is far from over.
"Make no mistake. We know that as successful as this operation was, it is just one battle in what is an ongoing war," he said.
More than 400 of the arrests were made Wednesday.
The Drug Enforcement Administration, the FBI and Immigration and Customs Enforcement worked on the effort with state and local law enforcement agencies.
Mexican police are holding one alleged heroin kingpin, Carlos Ramon Castro-Rocha, who is wanted in two U.S. states on drug charges. The Justice Department is working with Mexico to extradite him.
In Mexico, Ramon Pequeno, head of the anti-narcotics division of Mexico's federal police, said that U.S.-Mexico cooperation has been key in arresting traffickers.
People like Castro-Rocha "keep a low profile, manage significant amounts of drugs and money, are little known and don't belong to any traditional drug trafficking organization, which makes it difficult to identify and capture them," Pequeno said. "It is at this stage that the exchange of information and the collaboration with authorities from other countries is heightened."
At the news conference in Washington, Michele Leonhart, acting administrator of the DEA, described the law enforcement strategy as an effort to cut off and shut down the supply of drugs headed northward and the flow of drug profits and guns southward into Mexico.
Violent drug distribution networks in the Southwest pose a threat to U.S. border security, said assistant FBI director Kevin Perkins of the bureau's criminal investigative division.