Gunmen have laid siege to Mexico's western Jalisco state in retaliation for the army killing the head of the country's most powerful cartel, leaving tourists and locals on edge.

Multiple airlines canceled or redirected flights as armed forces opened fire in public places and set fire to businesses.

Unrest erupted after the army killed the leader of the Jalisco New Generation Cartel, Nemesio Oseguera Cervantes, nicknamed "El Mencho", in an operation on Sunday in the town of Tapalpa. He was initially wounded, but died en route to hospital.

Mexico's security minister, Omar Garcia Harfuch, said 25 members of the country's National Guard were killed in the operation, along with 30 criminal suspects. Armored vehicles, rocket launchers and other arms were seized.

El Mencho was a founder of the Jalisco New Generation Cartel, and the United States had issued a reward of up to $15 million for information leading to his capture.

Mexican Defense Minister Ricardo Trevilla said authorities tracked a "romantic partner" to one of the drug lord's hideouts, leading to the fatal shootout.

White House press secretary Karoline Leavitt said on Sunday that the US had "provided intelligence support to the Mexican government in order to assist with (the) operation".

Last year, Washington designated several Mexican cartels as foreign terrorist organizations, including the Jalisco New Generation Cartel, for trafficking drugs such as cocaine, heroin, methamphetamine and fentanyl, as well as kidnappings and murder, including of rival gang members and government officials.

After El Mencho's death, cartel members set up more than 250 roadblocks across 20 states, burned cars and engaged in shootouts.

The Chinese embassy in Mexico reminded Chinese citizens to stay alert to the local security situation. The embassy and consulates in Mexico are closely monitoring affected areas and reminded Chinese citizens to remain highly vigilant, pay close attention to notices and announcements issued by local government authorities, and strictly comply with them, it said.

In the event of an emergency, Chinese citizens were reminded to promptly call local police and contact the Chinese embassy or consulate in Mexico as appropriate.

Videos released online showed people running in Guadalajara International Airport, many dropping their bags and taking cover behind flight desks to protect themselves from chaos in the terminal.

Mexican President Claudia Sheinbaum applauded the country's security forces and called for calm. While she remains popular in the country, she has been facing pressure from Washington to take action against cartels.

Jalisco Governor Pablo Lemus Navarro activated an emergency "code red" in response to the violence, suspended public transportation across the state and urged people to stay home.

Mexico has deployed 10,000 troops to quell clashes. The government sent an additional 2,500 troops to Jalisco, bringing to 10,000 the troop deployment since Sunday.

Guadalupe Correa-Cabrera, a professor in the Schar School of Policy and Government at George Mason University in Virginia, said this was not the first time the leader of a cartel has been killed, arrested or extradited.

"This is part of the US strategy that has been applied in different Latin American countries, particularly in Mexico," said Correa-Cabrera, who is also co-director of the university's Terrorism, Transnational Crime and Corruption Center.

"The Jalisco Cartel, for example, is a very important criminal organization that does not have a single, critical leader," she said.

"Leadership is fragmented: the cells have different leaders and political protection at the local level, which allows them to perpetuate various types of criminal activity.

"We have seen this with other organizations, like the Sinaloa Cartel. Arrests or extraditions don't destroy the organization; family members or successors usually step in," she said.

"The root of the problem isn't the individual leader; it's the demand for drugs and the structure of the organization. We are not dealing with the financial or political protection structures, or corruption at official levels — just with individuals, who are replaceable. So, while such events may appear dramatic, they don't fundamentally dismantle the organization."