On Friday and Saturday, six clandestine synthetic drug labs were raided in Morelos, in the northern state of Chihuahua, following a three-month investigation, state prosecutor Cesar Jauregui told reporters.

The victims’ vehicle, which was leading an official convoy of five cars, skidded off the road and plunged into a ravine, he said.

The Americans killed were “instructor officers” who “were carrying out training tasks” as part of anti-drug cooperation between the US and Mexico, Jauregui said.

US ambassador Ronald Johnson paid tribute to the victims in an X post, identifying the Mexicans killed in the crash as the director of Chihuahua’s state investigation agency and an officer with that agency.

“We honour their dedication and tireless efforts to confront one of the greatest challenges of our time,” Johnson said.

“This tragedy is a solemn reminder of the risks faced by those Mexican and US officials who are dedicated to protecting our communities,” he said, adding it “strengthens our resolve to continue their mission.”