THE Mexican army killed the leader of the Jalisco New Generation Cartel (CJNG), Nemesio Ruben Oseguera Cervantes, “El Mencho,” on Sunday.

The move decapitates what had become Mexico’s most powerful drug cartel, but has thrust swaths of the nation into chaos.

Cars burned out by cartel members blocked roads at more than 250 points in 20 Mexican states, authorities said.

Jalisco’s capital, Guadalajara, was turned into a ghost town on Sunday night as civilians hunkered down. 

School was cancelled today in several states. Authorities in Jalisco, Michoacan and Guanajuato reported at least 14 dead, including seven National Guard troops.

Oseguera Cervantes was wounded in an operation to capture him on Sunday in Tapalpa, Jalisco, about a two-hour drive south-west of Guadalajara and he died while being flown to Mexico City, the Defence Department said in a statement. 

The state is the base of the cartel known for trafficking huge quantities of fentanyl and other drugs to the United States.

During the operation, troops killed four people at the location. Three more people, including Mr Oseguera Cervantes, were wounded and later died, the statement said. Two others were arrested and armoured vehicles, rocket launchers and other arms were seized.

White House press secretary Karoline Leavitt said via social media that the US government provided intelligence support for the operation. “‘El Mencho’ was a top target for the Mexican and US government as one of the top traffickers of fentanyl into our homeland,” she wrote. 

The US State Department had offered a reward of up to $15 million (£11m) for information leading to the arrest of El Mencho. 

In February 2025, the Trump administration designated the CJNG as a foreign terrorist organisation.

On Sunday, Mexico’s President Claudia Sheinbaum applauded Mexican security forces and called for calm in a social media post.