Updated

The top U.S. lawyer announced that authorities have arrested 175 people in the United States and in Italy on charges related to drug trafficking by an extremely violent Mexican drug cartel.

Attorney General Michael Mukasey says the coordinated arrests on Tuesday and Wednesday were part of a 15-month investigation into activity by the Gulf cartel.

Mukasey says the cartel is responsible for the importation and distribution of tons of cocaine, methamphetamine, heroin and marijuana from Central and South America into the United States.

The cartel is also believed to have laundered millions of dollars and has become a driving force behind escalating violence in Mexico and along the southwestern border of the U.S.

Mukasey said the investigation has dealt a "substantial blow" to the cartel.

In Atlanta, identified as a regional hub for the cartel, 43 people were arrested.

People were arrested in a dozen U.S. states as agents targeted the cartel's infrastructure, including transportation routes and distribution cells.

Through collaboration with Italian authorities, 10 people were also arrested in the Calabria region of Italy on charges related to drugs trafficked through New York.

The arrests announced Wednesday were part of a 15-month investigation that has resulted in 507 arrests and the seizure of about $60.1 million, 16,711 kilograms of cocaine, 1,039 pounds of methamphetamine, 19 pounds of heroin, 51,258 pounds of marijuana, 176 vehicles and 167 weapons.

Officials said indictments were unsealed Wednesday morning in U.S. District Court in Washington, D.C., for three alleged leaders of the cartel: Ezequiel Cardenas-Guillen, Heriberto Lazcano-Lazcano and Jorge Eduardo Costilla-Sanchez. All three are believed to be in Mexico and are considered priority targets by American authorities, who are working with their Mexican counterparts to catch them.