EL GUAYABO, Mexico — The explosions began before dawn, shaking the ground and rattling windows in the darkness. With them, residents said, came the telltale buzz of drones.

“We knew the devil was coming,” said Ana, a mother of six who grabbed her children and ran as gunmen moved in to do battle.

Weeks later, her town still bore scars. Holes were blasted into roofs where drones had dropped bombs. Craters gaped where land mines had exploded. Spent .50-caliber shells glinted in the dirt.

The clash was not in a war zone of Ukraine or the Middle East, and the combatants did not belong to any army. They were criminal groups, armed with military-grade weapons and fighting just a few hundred miles from the U.S. border, in Mexico’s western state of Michoacán.

Some of Mexico’s most formidable cartels are locked in a vicious arms race on multiple fronts. On one side, they are battling the Mexican government, which is under intense pressure from the United States to crack down on the drug trade. But they are also fighting one another for territory and resources, leaving a deadly toll among their members and the civilians caught in between.

US and Mexican Experts Agree on Cartels’ New Firepower

Now, President Donald Trump has ordered the Pentagon to begin using military force against certain drug cartels designated as terrorist groups. The directive has infuriated Mexico’s leaders, who have rejected the idea of U.S. forces on Mexican soil. But despite their disagreements about what actions to take, officials and security analysts in both countries agree that cartels are amassing new levels of firepower, transforming some groups into full-fledged paramilitary forces.

Drug smugglers and cartel gunmen no longer wield just handguns or automatic rifles, officials and experts say, but also Claymore land mines, rocket-propelled grenades, mortars built from gas-tank tubes and armored trucks mounted with heavy machine guns. They are burying improvised explosive devices to kill their rivals and modifying drones bought online to make attack drones, loaded with toxic chemicals and bombs.

“We cannot continue to just treat these guys as local street gangs,” Secretary of State Marco Rubio said in an interview with EWTN, a Catholic television network, last month. “They have weaponry that looks like what terrorists, in some cases armies, have.”

Mexican officials say that most of the military-grade weapons that powerful groups have acquired originated in the United States, and that up to 500,000 firearms are smuggled south each year. The officials say that criminals also reverse-engineer weapons, sometimes 3D printing parts to build them.

Nowhere are the consequences of this varied and growing arsenal starker than in the rugged hills of Tierra Caliente in Michoacán, a swath of fertile farmland and lush mountains that has become a strategic corridor for drug cultivation.

The battle for control there between rival groups — including the Knights Templar, La Familia Michoacana and the group with the most military power, the Jalisco New Generation cartel — has pushed the fight into a new, more brutal era.

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A War Transformed

Like other armed groups around the world, the cartels combine old and new weapons to deadly effect. Drones circle overhead in Michoacán, while roads and footpaths used by soldiers and civilians alike are seeded with IEDs.

Over the past two years, the state has recorded more mine explosions than anywhere else in Mexico, a chilling marker of the drug war’s evolution, experts say.

Caught between the shifting front lines of gangs and security forces are dozens of farming villages, their lemon and avocado fields tucked deep in the hills. Many have no phone service, effectively leaving them to fend for themselves. Ana, the mother in the attacked town, El Guayabo, gave only her first name for fear of retribution by criminals.

When fighting nears, most residents flee, sometimes for weeks or months. Some never return, leaving towns deserted. In nearly two years, more than 2,000 people have been displaced in Michoacán, rights groups say. Those who stay risk being trapped in the crossfire.

In the past five months alone, at least 10 civilians, including a 14-year-old boy, have been killed by hidden explosives while tending crops or walking to school, according to Julio Franco, an adviser with the Human Security Observatory, a group tracking violence.

Security analysts and Mexican officials say the cartels began to militarize in the mid-2000s, when Los Zetas, a group formed by former army members, brought battlefield discipline, encrypted communications and heavy weaponry to organized crime.

As Los Zetas acquired more of a military arsenal, so did its rivals, trying to compete. Mexico’s security forces, too, responded with ever more sophisticated equipment and tactics. The United States has also brought its own technology to bear, including by recently using drones that hunt for fentanyl labs.

In 2015, a sign of the transformation underway became evident when cartel gunmen in Jalisco state brought down a Mexican army helicopter with a rocket-propelled grenade launcher, killing six soldiers. It was the first time a criminal group had destroyed a military aircraft in Mexico.

By 2022, Mexican military intelligence reported that criminal groups were “routinely” deploying IEDs, drones and new tactics.

“We are witnessing the latest phase of the war: a move toward paramilitary-style tactics and capabilities,” said Alexei Chávez, a security analyst who has advised the Mexican army.

Many Cartel Weapons Come From the US

The Mexican government, under pressure from Trump, has pursued an aggressive crackdown, deploying thousands of troops to states like Michoacán. But officials have also blamed the United States for fueling the violence by manufacturing the guns that wind up in cartel hands.

President Claudia Sheinbaum of Mexico said in March that any real strategy against organized crime should begin by cutting off access to “high-powered, military-use weapons.” She said that 70% of those in Mexico came from the United States.

The cartels frequently flaunt their weapons, with gunmen posting videos and photographs online or in WhatsApp groups. In one recent image, a squad in military-style uniforms bearing the Jalisco cartel insignia cradled weapons including a Browning M2 .50-caliber heavy machine gun, a battlefield staple for the U.S. Army and militaries worldwide.

The weapons leave a path of destruction in their wake.

Pablo Fajardo, a resident of El Guayabo, recently returned to find his two-bedroom home a charred ruin, holes in its roof from bomber drones. “Fear and sadness, that’s all I feel,” he said. “All that effort and work I put into building my little house, and it was destroyed in a matter of days.”

This article originally appeared in The New York Times.

By Paulina Villegas/Adriana Zehbrauskas

c.2025 The New York Times Company