The U.S. Drug Enforcement Administration said that thanks to an undercover investigation launched more than two years ago, authorities have seized $186 million in cash and other assets from Mexican drug traffickers.

In a communique, the DEA said that "Project Below the Beltway" had the Sinaloa and Juarez drug cartels in its sights, along with violent street gangs linked to those outfits.

The investigation, carried out in 79 cities in the U.S. and abroad since May 2010, also resulted in the arrest of 3,780 people and the confiscation of 6,100 kilos (6 3/4 tons) of cocaine, 4,668 kilos (5 tons) of methamphetamine, 735 kilos (1,600 pounds) of heroin, and 158,584 kilos (175 tons) of marijuana, the statement said.

"The Sinaloa and Juarez Cartels are responsible for bringing multi-ton quantities of narcotics, including cocaine, heroin, methamphetamine and marijuana from Mexico into the United States," the DEA said.

They are also charged with money laundering millions of dollars gained in the illegal drug trade.

Those in custody face charges of drug trafficking, money laundering, violation of bans on the use of firearms and other crimes.

"These international organized crime regimes operate without borders and our ongoing investigations in the U.S. and overseas will continue to target its members wherever they operate," DEA Administrator Michele M. Leonhart said. EFE