MEXICO CITY (Reuters) - Mexico’s government said on Sunday it had arrested the wife of top drug lord Nemesio Oseguera on charges of laundering funds for his powerful cartel that is blamed for driving heroin shipments to the United States.

Known as “El Mencho,” Oseguera has risen to become Mexico’s most wanted drug lord after Joaquin “El Chapo” Guzman was extradited to the United States last year to face trial.

His wife, Rosalinda Garcia, was detained by marines in the Guadalajara suburb of Zapopon in the Western state of Jalisco, “without a shot fired” after a court ordered her arrest on organized crime and money laundering charges, Interior Minister Alfonso Navarrete told reporters at a media conference.

Navarrete said Garcia “allegedly administered resources” for her husband’s Jalisco New Generation Cartel, considered by authorities to be the most powerful Mexican drug cartel, with operations in the United States, Latin America, Africa, Europe and Asia.

In March, U.S. agents in Chicago named El Mencho public enemy No. 1 and blamed his gang for using “extreme violence” to expand their share of the heroin trade. The United States is offering $5 million for information leading to his capture.

The Jalisco gang has challenged Guzman’s Sinaloa cartel and other gangs in territories across Mexico over drug trafficking routes to the United States, fueling part of a surge in murder rates to the highest on records going back 20 years.

The surge in murders, kidnappings and extortion has hobbled backing for President Enrique Pena Nieto’s ruling party ahead of a July 1 presidential vote and helped fuel support for the leftist frontrunner, who is promising to curb violence by fighting corruption and poverty.

Navarrete said nearly 1,800 criminals had been caught since late January with the launch of operation Titian Shield, a federal plan to reduce violence in hot spots around the country.

He pointed to a drop in kidnapping rates in April and sharp decline in murder rates at the tourist resort of Los Cabos on the southern tip of the Baja peninsula and Colima state on the Pacific coast.

Yet, overall, murder investigations continued to climb in the first four months of 2018 to 8,900, up 17 percent from the same period last year, according to latest nationwide government data and Reuters calculations.