Mexico’s National Guard shot dead two Colombians and wounded four others in what the Defense Department said was a confrontation near the US border.

The Ministry of Foreign Affairs of Colombia declared in a statement On Sunday, all the victims were migrants who had been “caught in the crossfire”. He identified the dead as a 20-year-old man and a 37-year-old woman and put the number of injured Colombians at five, not four. There was no immediate explanation for the discrepancy. The victims were identified by the Ministry of Foreign Affairs as Yuli Vanessa Herrera Marulanda and Ronaldo Andrés Quintero Peñuelas.

Mexico’s Defense Department, which oversees the National Guard, did not respond to requests Monday for comment on whether the victims were migrantsbut a Colombian man who was not injured in the shootings was said to have been handed over to immigration officials, suggesting they were.

If they were migrants, it would mark the second time in just over a month that Mexican military forces have opened fire and killed migrants.

On October 1, President’s Day Claudia Sheinbaum took over, soldiers opened fire on a truck, killing six migrants in the southern state of Chiapas. An 11-year-old girl from Egypt, her 18-year-old sister and a 17-year-old boy from El Salvador died in that shooting, along with people from Peru and Honduras.

The latest shootings occurred Saturday on a dirt road near Tecate, east of Otay Mesa on the California border, which is frequently used by Mexican migrant smugglers, the department said in a statement late Sunday.

The the Department of Defense said a militarized National Guard patrol was attacked after spotting two vehicles — a gray pickup truck and a white SUV — in the area, which is near an informal border crossing and a wind farm known as the name of La Rumorosa.

A truck sped off and escaped. The National Guard opened fire on the other truck, killing two Colombians and wounding four others. There was no immediate word on their condition and no casualties among the guards involved.

A Colombian man and a Mexican man were found and detained unharmed at the scene, and departments said officers found a handgun and several magazines commonly used for assault rifles at the scene.

Sometimes Colombians were recruited as gunmen for the Mexican drug cartelswho are also heavily involved in migrant smuggling. But the fact that the survivor was handed over to immigration officials and that the Department of Foreign Affairs contacted the Colombian consulate suggests they were migrants.

Cartel gunmen sometimes escort or kidnap migrants as they travel to the US border. One possible scenario was that armed migrant smugglers could have been in one or both trucks, but that the migrants were basically unarmed bystanders.

The Defense Department said the three National Guard officers who opened fire have been taken off duty while the incident is investigated.

Former President Andrés Manuel López Obrador, who left office on September 30, gave the military an unprecedented role in public life and law enforcement; created the militarized Guard and used combined military forces as the country’s main law enforcement agency, replacing the police. The Garda has since been placed under the control of the army.

But critics say the military is ill-equipped to do civilian law enforcement work. Moreover, the lopsided death tolls in such clashes – where all the deaths and injuries occur on one side – raise suspicions among activists about whether there really was a confrontation.

For example, the soldiers who opened fire in Chiapas—who have been detained pending charges—claimed they heard “detonations” before they opened fire. There was no indication that any weapons were found at the scene.