Major Mexican drug lord Nemesio Oseguera, known as «El Mencho,» was killed in a military operation Sunday morning, the country’s Defense Department announced, marking one of Mexico’s most significant blows to organized crime amid pressure from President Donald Trump to intensify the crackdown on drug cartels.

The announcement came as government officials warned of clashes in Jalisco state and widespread criminal activity across the country, prompting the U.S. Embassy in Mexico to issue shelter-in-place advisories for multiple states.

On Sunday, Mexican troops reportedly conducted operations in Tapalpa, Jalisco, targeting Nemesio Rubén Oseguera Cervantes, a former police officer who became the elusive leader of the Cartel de Jalisco Nueva Generación (CJNG), a major supplier of fentanyl to the United States.

Known as «El Mencho,» Oseguera Cervantes carried a $15 million U.S. bounty and rose to power following the arrest of Joaquín «El Chapo» Guzmán, the former head of the Sinaloa Cartel. Over the past 15 years, CJNG has grown from a local criminal group into a global trafficking organization operating out of its stronghold in Jalisco.

A MEXICAN DRUG KINGPIN YOU’VE NEVER HEARD OF IS INFILTRATING SMALL-TOWN AMERICA

«I’ve just been informed that Mexican security forces have killed ‘El Mencho,’ one of the bloodiest and most ruthless drug kingpins,» U.S. Deputy Secretary of State Christopher Landau said in a post on X. «This is a great development for Mexico, the US, Latin America, and the world. The good guys are stronger than the bad guys.»

The Mexican Defense Department said the operation was conducted as part of bilateral coordination and cooperation with the U.S., whose authorities provided complementary intelligence that contributed to Oseguera Cervantes’ capture.

White House Press Secretary Karoline Leavitt confirmed that the U.S. «provided intelligence support to the Mexican government in order to assist with an operation in Talpalpa, Jalisco, Mexico, in which Nemesio ‘El Mencho’ Oseguera Cervantes, an infamous drug lord and leader within the Jalisco New Generation Cartel, was eliminated.»

«‘El Mencho’ was a top target for the Mexican and United States government as one of the top traffickers of fentanyl into our homeland. Last year, President Trump rightfully designated the Jalisco New Generation Cartel as a Foreign Terrorist Organization — because that’s exactly what it is. In this operation, three additional cartel members were killed, three were wounded, and two were arrested,» she wrote on X.

Smoke rises into the sky over Puerto Vallarta during an operation targeting cartel activity on Feb. 22, 2026. (Obtained by Fox News Digital)

During the capture, the CJNG ringleader became wounded and died en route to Mexico City, the Defense Department said.

Four others were reportedly killed at the scene of a shootout between Mexican troops and criminal suspects in Jalisco, with Oseguera Cervantes among three additional individuals who were wounded and later died.

Authorities said they detained two other members of the criminal organization and seized a range of weaponry, including armored vehicles and «rocket launchers capable of downing aircraft and destroying armored vehicles.»

Consequently, three members of the armed forces became injured and are receiving treatment.

TOURISTS IN MEXICAN SEASIDE CITY TOLD TO STAY ON RESORT AS GOVERNMENT WARNS OF ‘CLASHES’

Four others were reportedly killed in a Jalisco shootout during the operation (Gabriel Trujillo/Reuters)

Widespread criminal activity has been reported in Jalisco, the cartel’s stronghold, as well as in northern regions that serve as key border and transit corridors for the organization.

The Security Cabinet of the Government of Mexico noted that multiple buildings were reportedly damaged during the «violent incidents,» including roughly 20 branches of Banco del Bienestar, a state-run banking institution. 

At least 21 highways remain blocked, with authorities reporting that five have already been reopened.

Photos showed numerous roadblocks and burning vehicles, with dark smoke rising into the sky, across the country – tactics officials say cartels often use to slow or block military operations.

Photos and videos shared with Fox News Digital show thick, dark smoke rising over the skyline of the tourist city of Puerto Vallarta on Mexico’s Pacific Coast in Jalisco.

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Widespread criminal activity has been reported in Jalisco, the cartel’s stronghold. (Obtained by Fox News Digital)

«I’m watching the scenes of violence from Mexico with great sadness and concern. It’s not surprising that the bad guys are responding with terror. But we must never lose our nerve,» Landau said.

The Mexican National Guard and Army units from central Mexico and states neighboring Jalisco are currently mobilizing to reinforce security, the Defense Department said.

 «We remain in Code Red. We reiterate the recommendation to avoid leaving your homes. The clashes are occurring in several federal entities,» Jalisco state Governor Pablo Lemus Navarro added. 

At least 21 highways remain barricaded. (Michelle Freyria/Reuters)

Travel warnings have been issued for Jalisco, including Puerto Vallarta, Chapala, and Guadalajara; Tamaulipas, including Reynosa and other municipalities; and parts of Michoacán, Guerrero, and Nuevo León.

«Due to ongoing security operations and related road blockages and criminal activity, U.S. citizens in the named locations should shelter in place until further notice,» the U.S. Embassy & Consulates in Mexico said. 

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Complementary intelligence from U.S. authorities aided in the operation. (Michelle Freyria/Reuters)

The operation against Oseguera follows sustained pressure from the Trump administration on President Claudia Sheinbaum’s government, urging Mexico to step up its fight against drug trafficking amid threats of potential U.S. intervention.

Violenta reacción del cártel

Miembros del crimen organizado incendiaron vehículos para bloquear rutas. Foto: REUTERS/Gilberto Gallo

Mexican forces seized rocket launchers capable of shooting down aircraft during the operation Sunday that killed cartel boss Ruben «Nemesio» Oseguera Cervantes, known as «El Mencho,» underscoring how the Mexican Jalisco New Generation Cartel (CJNG) amassed military-style firepower over the years.

Authorities have previously linked CJNG to a 2015 attack in Jalisco in which cartel gunmen used rocket-propelled grenades to bring down a Mexican military helicopter – one of the starkest examples of a cartel directly engaging federal forces with battlefield-grade weapons.

The assault marked a turning point in how Mexican authorities viewed the group’s capabilities.

During Sunday’s raid, officials said security forces were attacked and returned fire, deploying aircraft and specialized units to carry out the operation. Authorities said troops seized armored vehicles and heavy weapons, equipment more commonly associated with armed conflict than routine law enforcement.

TOURISTS IN MEXICAN SEASIDE CITY TOLD TO STAY ON RESORT AS GOVERNMENT WARNS OF ‘CLASHES’

Mexican Special Forces, with aircraft assistance from the Air Force and National Guard rapid-reaction units, participated in the mission, highlighting the scale of force required to confront senior cartel leadership.

Former U.S. officials have described CJNG as operating more like a paramilitary organization than a traditional trafficking ring, using coordinated roadblocks, armed convoys and structured enforcement wings to assert control in contested regions.

In prior reporting, former Drug Enforcement Administration officials said the group commanded large numbers of gunmen and organized itself in a way that allowed it to deploy force quickly and visibly.

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CJNG is known for its paramilitary-style operations and structure. (Eduardo Verdugo, File/AP Photo)

CJNG’s tactics have included seizing vehicles and staging coordinated attacks in urban areas to demonstrate strength and deter rivals or security forces.

Over time, such displays reinforced its reputation as one of Mexico’s most heavily armed criminal organizations.

ALLEGED SINALOA CARTEL FENTANYL PRODUCER CHARGED IN NEWLY UNSEALED FEDERAL INDICTMENT

Smoke rises into the sky over Puerto Vallarta during an operation targeting cartel activity on Feb. 22, 2026. (Obtained by Fox News Digital)

The State Department issued a travel alert Sunday urging Americans in multiple Mexican states to shelter in place due to «ongoing security operations and related road blockages and criminal activity,» reflecting the instability that can follow major cartel confrontations.

In recent years, Mexican authorities have increasingly relied on military forces – rather than local police – to confront senior cartel figures as groups like CJNG expanded their reach and arsenals.

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The raid that killed «El Mencho» marked not only the removal of a powerful drug lord but also another example of how heavily armed cartels can challenge state forces in direct confrontations.