The U.S. State Department issued an advisory on Sunday instructing Americans in Jalisco State as well as in several other Mexican states to "shelter in place until further notice" following the elimination of Nemesio "El Mencho" Oseguera Cervantes, Mexico's most-wanted cartel boss.

With firefights breaking out across the country, radicals blocking key roads, and flights being canceled, many tourists really had no other option than to hunker down.

Mexican Army special forces, aided by the nation's air force and national guard, launched a military operation on Sunday aimed at capturing Oseguera Cervantes in Tapalpa, Jalisco.

'The United States will ensure narcoterrorists sending deadly drugs to our homeland are forced to face the wrath of justice.'

Under Oseguera Cervantes, 59, the Jalisco New Generation cartel became one of the most formidable criminal enterprises south of the border.

The State Department noted that the CJNG, which the Trump administration designated a terrorist organization last February, "has been assessed to have the highest cocaine, heroin, and methamphetamine trafficking capacity in Mexico, and over the past few years, includes the trafficking of fentanyl into the United States."

In addition to trafficking deadly drugs, the savage and allegedly cannibalistic CJNG developed a reputation for murdering Mexican police and rival drug traffickers. The cartel was also allegedly involved in several assassination attempts against Mexican government officials.

Mexican National Guard outside Specialized Prosecutor's Office for Organized Crime on Feb. 22. Photo by Daniel Cardenas/Anadolu/Getty Images

White House press secretary Karoline Leavitt indicated that the U.S. provided intelligence support to ensure the success of Sunday's operation. Mexican officials confirmed that "complementary information was provided by U.S. authorities within the framework of bilateral coordination and cooperation with the United States."

"'El Mencho' was a was a top target for the Mexican and United States government [sic] as one of the top traffickers of fentanyl into our homeland. Last year, President Trump rightfully designated the Jalisco New Generation Cartel as a Foreign Terrorist Organization — because that’s exactly what it is," Leavitt said in a statement.

"President Trump has been very clear — the United States will ensure narcoterrorists sending deadly drugs to our homeland are forced to face the wrath of justice they have long deserved," added Leavitt.

RELATED: What will replace the old world order?

Photo by Yilmaz Yucel/Anadolu/Getty Images

Mexico's Secretariat of National Defense indicated that while attacked during the operation, Mexican military personnel "repelled the aggression," resulting in "four members of the 'CJNG' criminal group dying at the scene and three others being severely wounded, who lost their lives during their airlift to Mexico City."

Oseguera Cervantes was among those wounded in the operation who apparently perished in transit.

Although Mexican and U.S. officials reported that Oseguera Cervantes was eliminated during the operation, the Mexican Secretariat of National Defense said that a forensic evaluation will nevertheless be undertaken to confirm that the cartel terrorist is dead.

In the wake of the operation, in which officials seized numerous armored cartel vehicles and rocket launchers, Mexican Army and National Guard troops mobilized to Jalisco and neighboring states to maintain a modicum of order.

Mexican President Claudia Sheinbaum — whose party has numerous members accused of being in bed with the cartels — underscored that "we must remain informed and calm."

'The good guys are stronger than the bad guys.'

Authorities in Jalisco, Michoacan, and Guanajuato indicated that seven Mexican National Guard troops were killed on Sunday along with seven others, reported the Associated Press.

Just before midnight on Sunday, the U.S. Dept. of State Bureau of Consular Affairs reiterated the need for American citizens to shelter in place, noting that "while no airports have been closed, roadblocks have impacted airline operations — most domestic & int’l flights are cancelled in Guadalajara and Puerto Vallarta."

Consular Affairs noted further that all rideshares are suspended in Puerto Vallarta and toll roads in various parts of the country are temporarily suspended.

One tourist claiming to be in Puerto Vallarta captured footage of thick columns of smoke billowing up on either side of his resort. Footage reportedly taken by a Canadian tourist stranded in Puerto Vallarta shows smoke-filled streets caused in one instance by a flaming bus.

David Miranda, a Chicagoan whose vacation in Puerto Vallarta has evidently gone off the rails, told WSB-TV, "There's blockages, there's cars on fires, there's buses blocking the roads. So nobody can take an Uber, can take a taxi, can take a bus. Everything is blocked."

"We don't know how we're going to get food, because it's Airbnbs," said Miranda. "So everything is closed, the corner stores — everything is closed."

Lefty Karkazis of San Francisco also found himself trapped in Puerto Vallarta.

"We were supposed to fly out of here at 2 p.m. So local time, at approximately 10 o'clock, we came downstairs, trying to get a taxi to go to the airport," Karkazis told KPIX-TV. "And [the hotel staff] told us that nothing is moving, all the roads are blocked because there's apparently a cartel operation that is affecting all the flights in and out."

His United Airlines flight was reportedly canceled.

"The next flight out for San Francisco from United is on Thursday. So we might end up staying until Thursday. I don't know," continued Karkazis. "We're just going to go from there. And the worst-case scenario, like I told my wife, we're just going to rent a car and start driving north."

The Trump administration commended the Mexican military on a job well done.

Deputy Secretary of State Christopher Landau said that the slaying of "one of the bloodiest and most ruthless drug kingpins" is a "great development for Mexico, the US, Latin America, and the world."

"The good guys are stronger than the bad guys," added Landau.

Like Blaze News? Bypass the censors, sign up for our newsletters, and get stories like this direct to your inbox. Sign up here!