The videos show officers in the city of Leon, about 150 miles northwest of Mexico City, forcing one of their colleagues to crawl through vomit and injecting carbonated water into the nose of another. An instructor, whose face can be seen in one video, barks out commands in English. Leon Police Chief Carlos Tornero told the Associated Press that the instructor is from a private U.S. security firm, but he declined to say which one.

“These are no more than training exercises for certain situations, but I want to stress that we are not showing people how to use these methods,” Tornero said.

The videos — first uncovered by a local newspaper, El Heraldo de León — ran repeatedly Tuesday on television stations here and prompted huge headlines in daily newspapers. La Jornada, a left-leaning Mexico City newspaper, declared, “Law enforcement in León teaches police to torture.”

Mexican and international human rights organizations expressed concern over the videos.

“This is troubling,” said Sergio Aguayo, founder of the nonprofit Mexican Academy for Human Rights. “In the past, torture was usually hidden. Now they don’t even bother.”

The videos show officers from Leon’s Special Tactics Group, known here by its Spanish-language initials, GET. In one video, a man who appears to be in extreme pain is shown kneeling in the dirt. An instructor — a bearded man of medium build in a black T-shirt, jeans and sunglasses — gives orders in English.

“Now get him to roll back into the puke,” the instructor tells one of the trainees.

The man, dressed in camouflage, can be seen rolling toward the vomit. But he does not touch it.

“He missed it. Roll back,” the instructor says.

“This punishment works,” a trainee, whose face is not shown, can be heard saying in English.

In another video, an officer — presumably playing the role of a witness — can be heard panting and gasping in pain as other officers squirt carbonated water into his nose. The man is being held in a dark room, and his arms are bound as he lies in a hole in the floor. Officers curse at him and talk of torturing him with rats and fecal matter.

Residents in several states have accused Mexican soldiers of committing hundreds of human rights violations, including rape and unjustified shootings, during a crackdown on drug cartels. Activists say Mexicans frequently do not make human rights complaints against local police for fear of retribution.