Mexican security forces killed Nemesio Oseguera, known as “El Mencho,” leader of the powerful Jalisco New Generation Cartel, during a military operation in western Mexico on Sunday. The raid sparked widespread retaliatory violence, including roadblocks, arson attacks, and transportation disruptions across several states.

Authorities said Oseguera was targeted during an operation in Tapalpa, a town on Mexico’s Pacific coast in Jalisco state. Mexico’s defense ministry confirmed that he was wounded during the raid and later died while being transported to Mexico City under heavy military escort.

The operation represents one of the most significant strikes against organized crime groups responsible for large-scale drug trafficking, including fentanyl shipments to the United States. President Claudia Sheinbaum has faced pressure from Washington to intensify efforts against cartels operating along the border.

U.S. officials acknowledged intelligence support in the mission. White House press secretary Karoline Leavitt said the United States assisted by providing intelligence and praised the cooperation with Mexican forces. The Trump administration described the outcome as a positive development and expressed appreciation for the Mexican military’s execution of the operation.

The raid encountered armed resistance. Security authorities reported that four individuals were killed at the site, while three others, including the cartel leader, were wounded and later died. Two additional suspects were arrested, and military units confiscated armored vehicles, rocket launchers, and other weapons. Three soldiers were injured and transported for medical treatment.

Following the killing, suspected cartel members launched retaliatory actions, blocking highways and burning vehicles and businesses across more than six states. No civilian deaths were immediately reported, though panic spread in several tourist and urban areas.

In Puerto Vallarta, a popular coastal resort city, tourists described chaotic scenes as dark smoke rose over the bay area. Airlines including Air Canada, United Airlines, Aeromexico, and American Airlines suspended flights to and from the region due to safety concerns.

Oseguera was a former police officer who later founded and led the cartel’s rapid expansion. Under his leadership, the organization grew into one of Mexico’s most powerful criminal groups, extending operations beyond drug trafficking into fuel theft, extortion, human smuggling, and financial fraud.

Security experts warned that the death of the cartel leader may trigger internal conflict within the organization. Some analysts predicted prolonged instability.

“There will definitely be skirmishes between the various factions, and these spasms of violence could last for years,” said Carlos Olivo, a former Drug Enforcement Administration assistant special agent in charge.

U.S. officials welcomed the operation. U.S. Deputy Secretary of State Christopher Landau called the killing a major step in the fight against organized crime.

“This is a great development for Mexico, the U.S., Latin America, and the world. The good guys are stronger than the bad guys,” Landau said, describing Oseguera as one of the most ruthless drug kingpins.

Mexican authorities said they would continue monitoring security conditions. President Sheinbaum said her government would strengthen cooperation with the United States in combating criminal networks while protecting national sovereignty and avoiding unilateral foreign military action inside Mexico.

She also stated that officials would release further information about the operation as investigations continue.

Security agencies are assessing whether the death of the cartel boss will lead to leadership fragmentation inside the cartel and potential violent power struggles among rival factions.

The operation is considered one of the most high-profile strikes against drug trafficking organizations responsible for exporting billions of dollars worth of narcotics into the United States each year.