Guadalajara, Mexico. Schools were closed in several Mexican states and authorities at home and abroad urged residents to stay indoors after widespread violence erupted following the army’s killing of the powerful leader of the Jalisco New Generation Cartel on Sunday.

Nemesio Rubén Oseguera Cervantes, known as “El Mencho,” led one of Mexico’s fastest-growing criminal networks, notorious for trafficking fentanyl, methamphetamine, and cocaine to the United States and for launching brazen attacks against government officials who challenged it.

He was killed during a shootout in his home state of Jalisco as the Mexican military attempted to capture him. Cartel members retaliated with violence across the country, blocking roads and setting vehicles ablaze.

President Claudia Sheinbaum urged calm, and authorities said late Sunday that they had cleared most of the more than 250 cartel roadblocks erected across 20 states. The White House confirmed the United States provided intelligence support for the operation and praised Mexico’s military for taking down one of the most-wanted criminals in both countries.

Mexico hoped the death of one of the world’s biggest fentanyl traffickers would ease pressure from the Trump administration to intensify its fight against drug cartels. But many residents remained hunkered down and on edge, waiting to see how the powerful group would respond.

Many Fear More Violence

Guadalajara, the capital of Jalisco and Mexico’s second-largest city, was nearly shut down Sunday as fearful residents stayed home.

Passengers arriving at the city’s international airport late Sunday were told it was operating with limited staff because of the violence. Most flights into the city were suspended.

Jacinta Murcia, a 64-year-old nutrition products vendor, nervously walked through the airport late Sunday night. Earlier in the day, travelers had sprinted and ducked behind chairs after reports of violence nearby.

Murcia scrolled anxiously through social media posts showing “El Mencho” and messaged her children, who were tracking her location as she tried to get home after dark.

“My plan leaving the airport is to see if there are any taxis, but I’m scared of everything — the blockades, a curfew, that something could happen,” she said. “I’m all alone.”

Authorities in Jalisco, Michoacán and Guanajuato reported at least 14 other deaths Sunday, including seven National Guard troops.

Videos circulating on social media showed tourists walking along beaches in Puerto Vallarta with smoke rising in the distance. Elsewhere at the airport, a group of elderly travelers gathered to discuss how to get home.

“We better all go together,” one said. “Go with God.”

A Diplomatic Boost and New Risks

David Mora, a Mexico analyst with the International Crisis Group, said the killing and the ensuing violence mark a turning point in Sheinbaum’s push to crack down on cartels and relieve U.S. pressure.

US President Donald Trump has demanded Mexico do more to curb fentanyl smuggling, threatening additional tariffs or unilateral military action if results are not delivered.

Early signs suggested Washington welcomed the operation. US Ambassador Ron Johnson praised the Mexican armed forces in a statement late Sunday, saying that “under the leadership of President Trump and President Sheinbaum, bilateral cooperation has reached unprecedented levels.”

But Mora warned the blow could also unleash further violence as rival criminal groups exploit a weakened cartel.

“This might be a moment when other groups see the cartel is weakened and seize the opportunity to expand their control,” he said.

“Since President Sheinbaum took office, the army has been far more confrontational against criminal groups,” Mora added. “This signals to the US that Mexico can do it — it doesn’t need US troops on Mexican soil.”

‘El Mencho’ Was A Top Target

Oseguera Cervantes was wounded during the operation in Tapalpa, Jalisco, about a two-hour drive southwest of Guadalajara, and died while being flown to Mexico City, the Defense Department said.

Troops came under fire during the operation and killed four people at the scene. Three others, including Oseguera Cervantes, were wounded and later died, the department said.

White House press secretary Karoline Leavitt said on X that the U.S. provided intelligence support for the mission, calling “El Mencho” a top target for both governments and one of the leading fentanyl traffickers into the United States.

The US State Department had offered a reward of up to $15 million for information leading to his arrest. The Jalisco New Generation Cartel, founded around 2009, is among Mexico’s most powerful and fastest-growing criminal organizations. In February 2025, the Trump administration designated it a foreign terrorist organization.

Sheinbaum has criticized the “kingpin” strategy of past administrations, which often triggered violent power struggles after cartel leaders were killed or captured. While she remains popular, security is a persistent concern, and she has faced mounting pressure from Washington since Trump returned to office a year ago.

The Jalisco cartel has been among the most aggressive in its attacks on the military, including downing helicopters. It pioneered the use of explosive-laden drones and land mines and in 2020 carried out a high-profile assassination attempt with grenades and high-powered rifles in the heart of Mexico City against the then police chief, now the federal security secretary.