MEXICO CITY — Mexico’s Defense Department said Saturday that 16 soldiers will be tried on military charges related to the killing of five men in the Mexican border city of Nuevo Laredo last month.

The department said the 16 soldiers were arrested Thursday and will be held at a military prison in Mexico City while awaiting trial before a military tribunal. The soldiers have been charged with violating “military discipline.”

The department said those trials would proceed independently of any charges that might be brought by civilian prosecutors. Under Mexican law, any abuses by soldiers involving civilians must go through civilian courts, but separate charges can be filed in military tribunals.

Mexico’s president described the May 18 slayings of five men caught on security camera footage as an apparent “execution” in the cartel-dominated city across from Laredo, Texas.

VA video from a store security camera published earlier this month showed a black pickup truck crashing full speed into a wall. A Mexican military truck pursuing it arrived shortly thereafter and ran into the passenger side of the pickup. The occupants of the truck were dragged out, kicked, and forced up against a wall. They were later found dead.

“This was an execution, and that cannot be permitted,” President Andrés Manuel López Obrador said Wednesday during his daily news briefing. “Those responsible are about to be turned over to the appropriate authorities.”

López Obrador has given the military an unprecedented role in Mexico’s life, everything from law enforcement to infrastructure projects to running trains and airports. He has staunchly defended the army’s honesty, but the military continues to be dogged by complaints of human rights abuses, especially in Nuevo Laredo.

The city is dominated by the Northeast drug cartel, and shootouts between cartel gunmen and soldiers or rival gangs are common.

The incident would be at least the second case of killings involving troops in Nuevo Laredo this year. On Feb. 26, soldiers killed five young men who were riding inside a vehicle.

The men were unarmed. A report by Mexico’s governmental human rights agency said the soldiers fired into the vehicle without giving verbal orders for it to stop. Angry neighbors attacked the soldiers, beating some of them.

In April, federal prosecutors filed homicide charges against four soldiers in that case.

That same month, a human rights organization in Nuevo Laredo sent a formal complaint to López Obrador. In it, a man said Mexican National Guard troops had fired on his vehicle in Nuevo Laredo, killing his pregnant 15-year-old girlfriend and a 54-year-old friend and wounding two others. A law enforcement crime scene report on the incident largely corroborated the account of the shooting contained in the complaint.

López Obrador claims the army has changed and has tried to depict incidents like the most recent killings as isolated acts by bad soldiers.