Thousands of migrants attempt the harrowing journey from Central America to the United States despite concerns that they are being increasingly targeted by drug gangs.
Mexico's National Human Rights Commission says that during six months of 2010, more than 11,000 migrants were kidnapped.
Amnesty International says six in ten female migrants travelling through Mexico are likely to be raped.
At the same time, Mexico's immigration agency has just dismissed all its personnel across seven states, after Central American migrants accused officials of being in league with organised crime.
Franc Contreras reports from Mexico.