On the evening of February 9, a Mexican navy helicopter hovering over the city of Tepic in the Pacific coast state of Nayarit laced a home in the city with a six-second stream of machine-gun fire.
Mexican officials said the gunfire came because gunmen had opened fire on marines with "high-caliber" weapons in the area and then barricaded themselves in the upper level of a house.
One official told the Associated Press that the Black Hawk helicopter had been called in for "dissuasive fire," meant to suppress fire from the house.
"To reduce the level of aggression and lower the risk of death among civilians and federal forces, (troops) repelled the attack with the support of dissuasive fire from a helicopter," a statement from the Mexican navy said.
Mexican marines were engaged in the initial exchange but were then joined by federal police and the army.
The first encounter led to the death of Juan Francisco Patron Sanchez, aka "H2," reportedly the leader of the Beltran Leyva Organization in Nayarit and the southern part of neighboring Jalisco state, and seven other suspects. A "second aggression" later near the city's airport ended with four more suspects dead.
The governor of Nayarit praised the operation as "surgical" and called it "proof that Nayarit is ... at peace." No Mexican personnel were killed.
While Mexican authorities have used the kind of "minigun" mounted on the helicopter in the past over rural areas, it's rare to see it used over urban areas.
The Mexican navy said it was deployed in line with rules of engagement. (There were reports early last year of Mexican military helicopters firing on homes during the search for "El Chapo" Guzmán.) Mexican authorities also recovered a grenade launcher and several rifles and pistols at the scene.
The exchange underscores the complexity and brutality that has come to characterize engagements between Mexican security forces and suspected criminals in Mexico, particularly the northwestern part of the country.
The Mexican government has acquired several Black Hawk helicopters from the US government through the Plan Merida initiative. Despite their sophistication, Black Hawks, like other helicopters, are not immune from cartel firepower.
In May 2015, members of the Jalisco New Generation cartel shot down a helicopter over Jalisco state, killing eight people on board. In September, suspected members of the Knights Templar cartel downed a state-government helicopter over the Tierra Caliente region of Michoacan, reportedly using a Barrett .50-caliber rifle.
Those are not the only antiaircraft weapons some of Mexico's criminal groups have at their disposal.
In April 2009, Mexican authorities in the northern border state of Sonora seized a weapons cache containing a .50-caliber antiaircraft machine gun mounted on a van, capable of firing 800 rounds a minute up to 1,500 meters away.
The following month, a hotel employee came across what appeared to be a SA-7 Soviet-made heat-seeking antiaircraft missile, which could be fired from the shoulder.
The missile was found abandoned on a beach called Playa Bagdad in northeastern Tamaulipas state, near where the Rio Grande empties into the Gulf of Mexico.
The origins of that missile and how it got there remain unclear. In February 2010, a Mexican man in the US pleaded guilty to trying to buy weapons — a Stinger missile and several antitank weapons — on behalf of the Sinaloa cartel.
In that cache was a Redeye man-portable air-defense system — a shoulder-fired antiaircraft missile.
Just hours after Patron, the Beltran Leyva's "H2," was killed, another member of the BLO — Daniel Isaac Silva Garate, known as "H9," was slain in a confrontation with police and marines nearby in Tepic.
The deaths of H2 and H9 come about two months after the BLO's purported leader, Alfredo Beltran Guzmán, who is believed to be the nephew of recently extradited Sinaloa kingpin Joaquín "El Chapo" Guzmán, was captured in the suburbs of Guadalajara, the capital of Jalisco.
While the BLO and the Sinaloa cartel were longtime allies, a falling out around 2008 pitted them against one another. The BLO suffered a series of blows as its leaders were killed and captured, while the Sinaloa cartel climbed to the top of Mexico's narco hierarchy.
That primacy seems to be in doubt now, however, as Guzmán's extradition appears to have set off a battle for control of the cartel. Gunfights have rocked the cartel's home base in Sinaloa state in recent weeks.
The 116 homicides recorded there in January were 50% more than registered in January last year, and dozens of people have reportedly been killed there in the last few days.
Reuters reports seeing footage of a truck-mounted machine gun firing during a confrontation in Culiacan, the Sinaloa state capital, though the news agency could not independently verify the location where the footage was recorded.
The spike in killing in Sinaloa comes amid a nationwide increase in deadly violence, with homicides rising 22% in 2016 over the previous year. With Trump's seemingly volatile approach to US-Mexico relations, observers on both sides of the border are concerned about the Mexican government's ability to staunch the bloodshed.
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