Schools were closed in several Mexican states Monday and authorities urged residents to remain indoors after widespread violence erupted following the killing of a top cartel leader in a military operation.

Nemesio Rubén Oseguera Cervantes, known as “El Mencho,” leader of the Jalisco New Generation Cartel (CJNG), died after being wounded during an army operation Sunday in Tapalpa, Jalisco, according to Mexico’s Defense Department. Officials said he was injured during the attempt to capture him and later died while being transported by air to Mexico City.

His death triggered a swift and violent response from CJNG members, who set vehicles ablaze and used them to block highways in nearly a dozen states. Thick smoke from burning cars filled the air in multiple regions, and parts of Guadalajara, the capital of Jalisco, appeared largely deserted Sunday night as residents stayed inside.

Local authorities canceled classes in affected areas, and both Mexican officials and foreign governments issued advisories urging people to shelter in place amid the unrest.

Oseguera Cervantes, 59, had long been one of Mexico’s most wanted figures. The CJNG, based in Jalisco state, is considered one of the country’s most powerful criminal organizations and is accused of trafficking large quantities of fentanyl and other narcotics into the United States.

Mexican officials have framed the operation as a significant blow against organized crime. However, the immediate aftermath underscored the cartel’s capacity for rapid retaliation and its reach across multiple regions of the country.