Their capture shone a spotlight on the growing involvement of foreign ex-military personnel with Mexican drug traffickers.

More than 40 explosive devices were seized along with other weapons in the western state of Michoacan, according to statements from the national and local governments.

In total, 17 suspected members of a criminal group, including a dozen Colombians, were detained in the municipality of Los Reyes, authorities said.

The blast late Tuesday destroyed the armored vehicle in which the Mexican troops were traveling, according to an internal military report seen by AFP.

Military planes and helicopters were deployed to help the casualties, it said.

The area is home to the Jalisco New Generation Cartel, one of the country's most powerful drug trafficking groups.

The disarmament of the FARC guerrilla group in 2017 and cuts to Colombia's military budget are part of the reason for the presence of foreign former soldiers in Mexico, independent security expert David Saucedo said.

Some come directly from Colombia, "and others were mercenaries in Ukraine," he told AFP.

For years, Colombian mercenaries, mostly retired military personnel, have fought in conflicts including in Afghanistan, Yemen and Iraq.

In 2023, Colombian gunmen killed Ecuadorian presidential candidate Fernando Villavicencio, while in 2021, Colombian hitmen assassinated Haitian president Jovenel Moise.

Cartels are targeting former Colombian military personnel and guerrillas for their knowledge of explosives, Saucedo said.

In October 2023, Michoacan security officials reported a "Colombian cell" dedicated to manufacturing explosives had been dismantled.

The involvement of former Mexican and foreign military personnel with cartels is not new.

Former members of an elite Mexican army unit founded the bloodthirsty Zetas cartel in the late 1990s and recruited deserters from the Guatemalan special forces.

The recruitment of Colombians "is a reaction to the militarization process" that Mexico has been experiencing since the government launched a war on cartels in 2006, Saucedo said.

Criminal groups in Michoacan have a history of planting improvised landmines and attacking security forces with explosive-laden drones.

Several soldiers have been killed in similar explosions in the past.

Criminal violence, most of it linked to drug trafficking, has claimed around 480,000 lives in Mexico since 2006 and left more than 120,000 people missing.

US President Donald Trump has designated six Mexican drug trafficking groups as terrorist organizations, fueling speculation that he might order military strikes against them.