(CNN) -- Mexican authorities say they've rescued 94 migrants who were crammed into the back of a hauling truck in "subhuman conditions."
They came from as far away as Nepal and as nearby as Guatemala, paying thousands of dollars to get to the United States, authorities said. Seven of them were minors. They showed symptoms of asphyxiation and serious lesions on their hands and feet when they were rescued, Mexico's National Migration Institute said.
X-ray equipment detected the migrants at a checkpoint in the southern Mexican state of Chiapas early Tuesday morning.
The driver of the truck has been turned over to prosecutors on suspicion of human trafficking, and the migrants are receiving medical, psychological and legal assistance, Chiapas state prosecutors said in a statement.
Photos released by local police show migrants sitting on the ground as an official toting a stethoscope tends to them. It was not immediately clear where the migrants would go.
The group included 45 Guatemalans, 23 Salvadorans, 10 Nepalese and 9 Bangladeshis and 7 Hondurans, authorities said.
"The migrants had paid different amounts for the transport, according to their nationality," the migration institute said. "In the case of the Central Americas, the tariff was between $4,000 and $5,000, and the Asians from $6,000 to $8,000."
Last week, Mexican authorities rescued 81 migrants they said were held captive in the border city of Reynosa.
And in June, authorities said they rescued 165 migrants who were kidnapped as they tried to cross into the United States.
Experts say many migrants passing through Mexico on their way to the United States are victims of violence along the Mexico-U.S. border, but the journey is perilous from the moment it begins. And the danger has grown as Mexico's drug gangs expand their reach.
CNN en Español's Eduardo Aragon contributed to this report.