Thousands of people from Central America make their way across Mexico every year, hoping to escape grinding poverty and insecurity back home and make better lives for themselves and their families in the USA.
Many of them travel on foot or on the top of freight trains. Their journey is full of dangers.
Kidnapping is a constant fear. Thousands of women, men and children are abducted every year. Victims whose desperate relatives cannot raise the ransom face torture or death.
Rape is widespread. It is believed that as many as six out of every 10 migrant women and girls experience sexual violence during the journey.
Killings are frequent. Nobody knows how many migrants die on the journey.
Criminal gangs carry out most of these attacks, but Mexican police officers and other officials have been implicated in assaults, working with criminal gangs to extort money from migrants. Despite government commitments to improve migrants security, those who commit these crimes are almost never brought to justice.
Many families may never know what happened to the sons, daughters or other family members who set out in search of a better future. Hundreds of migrants have disappeared in Mexico on their way to the USA.
The photos of this slideshow are part of an exhibition organized by Amnesty International which will open to the public on 16 October in Mexico City.