Mexican Army Soldiers and National Guardsmen continued to battle transnational criminal organizations, or TCOs, in Sinaloa in December 2025, conducting operations across the home territory of the Sinaloa Cartel, which has been designated a foreign terrorist organization by the United States. Three operations in Sinaloa from December 11-12 netted dozens of improvised explosive devices (IEDs), guns, ammunition and laboratory equipment used to produce the deadly opioid fentanyl. Soldiers and Guardsman also discovered a vehicle outfitted with homemade armor in Tamaulipas and more weaponry and tactical gear in Michoacán, according to a news release from the Mexican Secretariat of National Defense (DEFENSA).
A surveillance and reconnaissance patrol in the town of Puerto de la Esperanza in the municipality of Badiraguato in Sinaloa found three rifles, nine magazines, 285 cartridges, a grenade launcher and 40 IEDs, the release stated. A drone and vehicle also were seized. The drones were destroyed on site. Nearby, in La Noria de Arriba, another patrol seized three more guns along with 15 magazines and 159 cartridges.
Still more patrols in El Tancote, near Mocorito, and Canamaca and Los Cedros in Culiacán found and destroyed seven synthetic drug manufacturing supply areas, netting 7,220 liters of chemical substances. The troops also seized five reactors, four capacitators and two centrifuges used to make the drugs.
“The seized evidence was made available to the competent authorities to determine its legal status and continue with the corresponding investigations; it should be noted that these activities were carried out in strict adherence to the rule of law and with full respect for human rights, contributing to the preservation of freedoms, order, and public peace in Sinaloan society,” the release stated.
In Tamaulipas, meanwhile, Mexican Army Soldiers and National Guardsmen in the IV Military Region, headquartered in Reynosa, located three vehicles with improvised armor and ammunition in the village of Valadeces, near Gustavo Díaz Ordaz. “In this way, the National Guard, the Army, and the Air Force reaffirm the federal government’s unwavering decision to inhibit organized crime activities and reiterate their commitment to protect and safeguard the peace and security of the population,” the December 14 DEFENSA news release stated.
Finally, two operations in Michoacán seized three guns, nearly 200 cartridges, two vehicles and tactical gear, according to DEFENSA.
The releases didn’t name a specific cartel. In 2025, the U.S. government has designated six Mexican TCOs as foreign terrorist organizations: Gulf Cartel (Cártel del Golfo), Jalisco New Generation Cartel (Cártel de Jalisco Nueva Generación), New Michoacan Family (La Nueva Familia Michoacana), Northeast Cartel (Cártel del Noreste), Sinaloa Cartel (Cártel de Sinaloa) and United Cartels (Cárteles Unidos). The oldest, the Sinaloa Cartel, was founded in the late 1960s as a marijuana smuggling operation.
Mexican President Claudia Sheinbaum has stepped up counter-TCO efforts since assuming office in October 2024, deploying 10,000 National Guardsmen to the Mexico-U.S. border, restructuring Mexico’s counter-TCO response and raiding cartel fentanyl labs. In September 2025, U.S. Secretary of State Marco Rubio said Mexico-U.S. cooperation on counter-TCO efforts is the “closest cooperation we’ve ever had, maybe between any country, but definitely between the U.S. and Mexico.”