More than three dozen people have died in a fire at an immigration detention centre in northern Mexico, near the border with the US, an official said.
The Mexican official with the National Immigration Institute said at least 40 people died and dozens were injured in the blaze.
Those injured have been taken to four local hospitals.
The institute said 68 adult men from Central and South America were being housed at the facility.
Mexico’s president Andres Manuel Lopez Obrador has said the fire was started after migrants fearing deportation set mattresses ablaze at the detention centre.
“They never imagined that this would cause this terrible misfortune,” Mr Obrador said.
Footage from the scene showed soldiers and firefighters helping the injured to safety from inside a building at the National Migration Institute in Ciudad Juarez, near El Paso in Texas.
Some were treated at the scene by paramedics and others taken to nearby hospitals for treatment, according to local media reports.
The fire reportedly broke out in a part of the complex designated for men only. It is not known how it started.
It comes after US officials earlier this month stopped hundreds of migrants – mostly Venezuelans – from entering the country after a large group tried to force their way past Mexican soldiers on the border.
Many have been frustrated by a new asylum process introduced by the Biden administration.
It requires asylum seekers to book a meeting with US officials first, but users say they have been unable to secure appointments on the government app due to glitches and high demand.
They say it has led to families being split up at the border – with no knowledge of when they will be reunited.
Critics of the process have highlighted technical problems with the app and say it is unclear how many appointments are available every day.
The US Department of Homeland Security has said updates to the app, called CBP One, will simplify and speed up the process.
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Under the new rules, migrants who do not schedule an appointment at a US border port of entry or use humanitarian programmes available to certain nationalities would be ineligible for asylum except in certain cases.
They must also first seek protection in countries they pass through to be able to claim asylum once in the US.
The move aims to deter unauthorised crossings and mirrors similar efforts under Donald Trump, which were blocked in court.
However, officials insist the measure is different from Mr Trump’s, largely because there is room for exemptions and because it has made other legal pathways available, particularly humanitarian parole for Cubans, Haitians, Nicaraguans, Venezuelans and Ukrainians.