Mexican forces killed Nemesio Oseguera Cervantes, known as “El Mencho”, the leader of the Jalisco New Generation Cartel (JNGC), in a high-risk operation in the western state of Jalisco on Sunday.

Security forces tracked El Mencho, one of the United States’s most wanted fugitives, to a property in the mountain town of Tapalpa, central-western Mexico, after receiving intelligence linked to a close associate.

Troops launched a predawn raid on Sunday, triggering hours of gun battles and a wave of violence across several states.

The killing marks the most significant blow against organised crime since Mexican and US authorities recaptured Joaquin Guzman, known as “El Chapo”, nearly a decade ago.

Here is what we know about how the operation to capture El Mencho unfolded on Sunday.

Who was El Mencho?

El Mencho, 59, was believed to be a former police officer. He was from Michoacan, western Mexico, and built a vast criminal enterprise over more than 30 years.

US authorities convicted him of heroin trafficking in the mid-1990s, and he served a prison sentence in the US before returning to Mexico, where he rose rapidly within the drug underworld.

Around 2009, he founded the JNGC, which expanded rapidly to become one of Mexico’s most powerful and violent cartels.

The group trafficked cocaine, methamphetamine and fentanyl to the United States and smuggled migrants northwards.

It also earned notoriety for deploying military-style tactics, including armed drones and improvised explosive devices, and for launching direct assaults on security forces.

How did the operation unfold?

On February 20, acting on new intelligence from an associate of one of El Mencho’s romantic partners, Mexican authorities began surrounding the site in Tapalpa where El Mencho was believed to be hiding.

Special forces, backed by the National Guard, military aircraft and helicopters, sealed off the area before dawn on February 22.

Cartel gunmen opened fire as soldiers advanced. Security forces returned fire, killing several suspected CJNG members. El Mencho and members of his inner circle fled to a nearby wooded cabin complex, where a second firefight erupted.

Soldiers eventually found a wounded El Mencho alongside two bodyguards. The authorities airlifted him to a medical facility, but he died during the flight.

A US defence official told Reuters that a US military-led intelligence task force focusing on drug cartels had supported the operation.

What happened in the aftermath of the operation?

The raid set off an immediate response from cartel bosses. The defence ministry identified a senior JNGC figure known as “El Tuli”, El Mencho’s right-hand man and a top financial operator within the cartel, as the organiser of coordinated attacks in Jalisco.

Mexican authorities said he orchestrated roadblocks, arson attacks and assaults on government facilities, and offered a bounty of 20,000 pesos ($1,100) for the killing of each member of the military, following the February 22 operation.

Later the same day, security forces tracked him to El Grullo, a small town about 180km (112 miles) southwest of Guadalajara. He attempted to flee, firing on officers who killed him in the ensuing clash.

Violence spread across Mexico rapidly. Cartel members torched vehicles and blocked highways in several states.

Airlines cancelled flights to Puerto Vallarta, a Pacific resort city in the western state of Jalisco, as plumes of smoke rising over parts of southern Mexico grabbed international headlines.

Schools and universities suspended classes, and local authorities urged residents to remain indoors.

By Monday, authorities reported that at least 30 suspected gang members, 25 National Guard troops and one civilian had been killed in the unrest following the operation.

Security forces arrested more than 70 people across seven states and recorded at least 85 cartel-related roadblocks on Sunday alone.

The killing of El Mencho removes one of Mexico’s most feared crime bosses.

While Mexico has long pursued a strategy of targeting cartel leaders, the experience has shown that removing kingpins can fracture groups and spark internal power struggles, analysts say.