At least 40 were killed on Monday after a blaze broke out at a government-run migrant detention centre in Ciudad Juarez, a city in northern Mexico.
The fire was reportedly started by migrants protesting against their deportation near the US border.
United Nations High Commissioner for Refugees Filippo Grandi expressed solidarity with relatives of the victims and appealed to countries in the region "to deal in a humane, just, effective manner with growing population flows through the Americas."
The fire broke out after 10 pm. About 68 men from Central and South America were being held at the facility.
According to Guatemala’s Institute of Migration, 28 Guatemalans were among the dead.