One of Mexico’s most notorious drug lords, Nemesio Oseguera, or “El Mencho,” was killed in a military raid on Sunday, sparking widespread retaliatory violence.

President Claudia Sheinbaum has been under mounting pressure from Washington to intensify her offensive against drug cartels blamed for producing and smuggling drugs, particularly the synthetic opioid fentanyl, across the border to the US. Mexico’s Security Minister Omar Garcia Harfuch said that 27 members of the National Guard died in attacks in Jalisco state.

Oseguera, 60, the mastermind of the powerful Jalisco New Generation Cartel (CJNG) died in custody after being injured in a military operation by Mexican special forces in the town of Tapalpa on Mexico’s Pacific coast in Jalisco state, according to Mexico’s defense ministry.

His corpse arrived in Mexico City on Sunday afternoon in a heavily guarded convoy of National Guard troops. Reuters had reported on Sunday that a new US-military-led task force played a role in the raid led and carried out by Mexican forces. White House press secretary Karoline Leavitt later posted on social media that the United States provided intelligence support.

Leavitt added that the Trump administration “commends and thanks the Mexican military for their cooperation and successful execution of this operation.”

After reports of El Mencho’s death, cartel henchmen blockaded highways with burning cars and torched businesses in more than a half a dozen states. In Jalisco’s popular beach resort of Puerto Vallarta, frightened tourists on social media described a “war zone” as plumes of dark smoke rose into the sky from around the bay. Air Canada, United Airlines, Aeromexico and American Airlines suspended flights in the area.