The 52 passengers travelling on the bus on Mexico's Miahuatlan-Coixtlahuaca Highway included 10 passengers from Venezuela, the INM said, adding they had appointments to seek legal entry to the United States.
Some 36 passengers were injured and taken to hospital after the bus crashed with a trailer in the early hours of the morning, officials from the state of Puebla said in a separate statement.
Nine of the injured were Venezuelan and of those, three remain hospitalised, according to the INM, which said support would be given to return the body of the deceased to Venezuela.
Local media had earlier reported that those killed in the crash were mostly migrants from Venezuela.
A video shared on X by the local Red Cross unit showed a mangled white bus lying on its side while rescue teams worked in the dark.
A passenger bus skidded off the main highway and plunged into a swollen river in Nepal's Bagmati province on Wednesday, killing at least eight people and leaving at least 15 others injured, according to a media report.
