Guards at a detention centre in northern Mexico walked away when migrants placed mattresses against the bars of their cell and set them on fire, surveillance video has shown.
Staff at the immigration detention facility in Ciudad Juarez, which is across the US border from El Paso, Texas, and a major crossing point for migrants, made no apparent attempt to release the men before smoke filled the room and killed 38 of them, the footage shows.
Hours after the fire broke out late on Monday, rows of bodies were laid out under silver sheets outside the centre.
At the time of the blaze, 68 men from Central and South America were being held at the facility, the agency said. The institute said almost all were from Guatemala, Honduras, Venezuela and El Salvador.
In the video, two people dressed as guards rush into the camera frame, and at least one migrant appears by the metal gate on the other side. But the guards did not appear to make any effort to open the cell doors and instead ran away as billowing clouds of smoke filled the structure within seconds.
Adan Augusto Lopez, Mexico’s interior secretary, confirmed the authenticity of the video.
Mexico’s president Andres Manuel Lopez Obrador said the fire was started by migrants in protest after learning they would be deported.
“They never imagined that this would cause this terrible misfortune,” Mr Lopez Obrador said.
The deaths forced the government to rent refrigerated trailers to hold the migrants’ bodies, Chihuahua state prosecutor Cesar Jauregui told reporters.
Viangly Infante Padron, a 31-year-old Venezuelan migrant seeking asylum in the US with her husband and three children, had been waiting outside the detention centre for his release when the fire broke out.
“The ones they let out were the women, and those (employees) with immigration,” she said.
“The men, they never took them out until the firefighters arrived.”
She said she saw several dead bodies before finding her husband in an ambulance.
“I was desperate because I saw a dead body, a body, a body, and I didn’t see him anywhere.”
More than 30 migrant shelters and other advocacy organisations published an open letter on March 9 that complained about the criminalisation of migrants and asylum seekers in the city.
It accused authorities of abusing migrants and using excessive force in rounding them up, including complaints that municipal police questioned people in the street about their immigration status without cause.
Migrant advocates said on Tuesday that the immigration facility was over capacity and that the site of the fire was small and lacked ventilation.
“You could see it coming,” the advocates’ statement said. “Mexico’s immigration policy kills.”
The “extensive use of immigration detention leads to tragedies like this one,” Felipe Gonzalez Morales, the United Nations special rapporteur for human rights of migrants, said via Twitter.
In keeping with international law, immigration detention should be an exceptional measure and not generalised, he wrote.
Mexico has emerged as the world’s third most popular destination for asylum seekers, after the US and Germany. But it is still largely a country that migrants pass through on their way to the US.