WASHINGTON (AP) - Law enforcement agencies have arrested more than 2,200 people in a 22-month 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.
Attorney General Eric Holder told a news conference the initiative struck a significant blow against the cartels, but called it "just one battle in what is an ongoing war."
Over 400 of the more than 2,200 arrests were made Wednesday.
The Justice Department says the nearly-two-year probe has led to the seizure of $154 million in currency, over 1,200 pounds of methamphetamine, 2.5 tons of cocaine, over 1,400 pounds of heroin and 69 tons of marijuana.
The Drug Enforcement Administration, the FBI, and Immigration and Customs Enforcement worked on the effort with state and local law enforcement agencies.
Among those arrested in recent days was Carlos Ramon Castro-Rocha, believed by law enforcement agencies to be among the leaders of organizations importing narcotics to the U.S.
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 Carlos Ramon 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 Drug Enforcement Administration, 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.
Associated Press writer Olga R. Rodriguez in Mexico City contributed to this report.