The Mexican army announced on Sunday the death of Rubén Nemesio Oseguera Cervantes, known as “El Mencho,” one of the world’s most wanted drug traffickers, who was killed during an operation carried out by Mexican federal forces. His death has triggered unrest across parts of the country, with Mexico’s president calling for calm.

His capture had been highly sought by the United States, which had offered a reward of up to $15 million for information leading to his arrest.

A former police officer, Oseguera led the powerful Jalisco New Generation Cartel (CJNG), which in recent years became one of the most powerful criminal organizations in Mexico, rivaling the Sinaloa Cartel, formerly headed by jailed drug lord Joaquín "El Chapo" Guzmán, who is currently imprisoned in the United States.

He died during a federal operation in the mountainous region of the state of Jalisco, in western Mexico. According to the army, “El Mencho” was wounded during an operation in the town of Tapalpa and died while being airlifted to Mexico City.

His death marks one of the most significant blows to drug trafficking since the arrest of the founders of the Sinaloa Cartel.

Washington welcomed the operation targeting “El Mencho.” U.S. Deputy Secretary of State Christopher Landau described it as a “major event for Mexico, the United States, Latin America, and the world.”

In total, seven suspected criminals were killed and three soldiers were injured during the operation. Two CJNG members were arrested, and authorities seized multiple weapons, including rocket launchers capable of downing aircraft and destroying armored vehicles.

The Mexican embassy in Washington stated that the United States had provided intelligence support for the military operation as part of bilateral coordination and cooperation.

His death sparked a surge in violence. Armed individuals blocked major highways in Jalisco using burning vehicles and trucks. Roadblocks were also reported in neighboring Michoacán, where the group is active, as well as in Guanajuato, Puebla, and Sinaloa.

Mexico’s president, Claudia Sheinbaum, urged the population to remain calm. “We must stay informed and remain calm,” she wrote on X.

The U.S. Embassy in Mexico advised American citizens in affected areas to shelter in place until further notice due to ongoing security operations and criminal activity. The warning covered several regions, including major tourist cities such as Cancun, Guadalajara, and Oaxaca, as well as the state of Baja California.

Several North American airlines canceled dozens of flights to various Mexican cities.

Sports events were also disrupted. A Mexican first-division match between Querétaro and Juárez was suspended due to the violence. The women’s league postponed the clásico between Guadalajara and América at Akron Stadium in Zapopan, and the second-division Liga Expansión delayed the match between Tapatío and Tlaxcala, scheduled at Gregorio “Tepa” Gómez Stadium in Jalisco.

Founded in 2009, Oseguera’s cartel became one of the most violent drug trafficking organizations in Mexico, according to the U.S. Department of Justice. Washington has designated the group as a terrorist organization and accuses it of trafficking cocaine, heroin, methamphetamine, and fentanyl.