San Francisco Frontiers - The key to taking down Mexico's most-wanted narco? His girlfriend

The 59-year-old Oseguera, nicknamed "El Mencho," was wounded in a clash with soldiers on Sunday and died while being airlifted to hospital.

The operation was launched when Mexican military intelligence agents, supported by the US military's Northern Command, learned that the woman in question planned to rendezvous with the drug lord in Tapalpa, some 130 kilometers from Guadalajara, the capital of Jalisco state.

Mexican Defense Secretary Ricardo Trevilla told reporters at a press conference Monday that the woman, "one of the romantic partners of 'El Mencho,'" was brought to a house in Tapalpa by a trusted associate.

On Saturday, she met with Oseguera and then left, leaving Oseguera in the house with his security detail, Trevilla explained.

The National Guard's Special Immediate Reaction Force blueprinted the operation for the assault on Sunday with both land and air maneuvers.

The soldiers approached the area without entering Jalisco "to keep the secret and thus retain the element of surprise," Trevilla said.

Once they confirmed the presence of Oseguera, who was wanted for organized crime and weapons possession, they decided to raid the ranch.

- 'Pretty violent' -

"Honestly, it was a pretty violent attack," Trevilla said, specifying that Oseguera was apprehended in possession of an arsenal that included assault weapons and two rocket launchers.

The kingpin's security escorts, who have made a name defying state forces, had used these types of bazookas before.

In 2015 they shot down a military helicopter, helping the drug trafficker evade capture.

"El Mencho" didn't have the same luck Sunday. As they fled, he and his close circle of guards took cover in a forested area surrounding a complex of cabins.

He was surrounded by the soldiers again, who found him hiding in the undergrowth, the head of the military explained.

His gunmen managed to hit a military helicopter, which had to make an emergency landing in a nearby base.

In the midst of the gunfight, the soldiers wounded Oseguera alongside two of his escorts:

All three were airlifted to a hospital in Guadalajara but perished en route, Trevilla said.

The bodies were then transported by airplane to Mexico City and handed over to the General Prosecutor's Office.

Security Secretary Omar Garcia Harfuch said that Osegeura's remains would be handed over to his family.

It is not yet known where he will be buried.

Authorities also announced the death of his right-hand man.

Hugo H., known as "El Tuli," was found in El Grullo, another town in Jalisco, from where he directed road blockades, the burning of vehicles, and retaliatory attacks against military institutions after his boss's death.

"He was offering 20,000 pesos ($1,150) for every soldier who was killed," Trevilla said.

Like Oseguera, "El Tuli" died Sunday as he tried to flee. He was carrying an assault weapon, a pistol and the equivalent of nearly $1.4 million on him when he died, Trevilla added.

The death of Oseguera unleashed a wave of violence across 20 out of Mexico's 32 states, marked by hundreds of roadblocks and torchings of vehicles.

On Monday, calm returned to most of the country.

The government has deployed around 10,000 soldiers as a dissuasive measure.

But blockades continued in isolated parts of Jalisco and neighboring Michoacan state.

W.Thompson--SFF