A group of Central American women who spent 19 days searching for their missing children in Mexico used the tour to highlight the dangers facing migrants passing through the country en route to the United States.

The “caravan”, as it was called, covered 14 Mexican states, starting in Tabasco in the south and finishing on November 3 in Ciudad Hidalgo, Chiapas, on the Guatemalan border. The 38 mothers and other relatives of missing migrants, who came from El Salvador, Honduras, Guatemala and Nicaragua, met civil organisations and government bodies to appeal for better protection for migrants, and for action on the cases of those who had disappeared.

Records from Mexico’s National Migration Institute show that Guatemalan, Honduran, El Salvadorean and Nicaraguan nationals account for most of the people who head through Mexico in the hope of entering the US. They account for 92-95 per cent of the people held in Mexico’s immigrant detention centres.

The Mesoamerican Migrant Movement, one of the groups that organised the caravan, claims that more than 70,000 migrants disappeared from 2006 to 2012.

Migrants are prey to armed gangs which use extreme violence to extort money and demand ransoms, with apparent impunity.

According to Amnesty International’s latest global report covering 2011, “Central American migrants travelling through Mexico in their tens of thousands were kidnapped, tortured, raped and killed by criminal gangs, often with the complicity of public officials. In the case of irregular migrants, fear of reprisals or deportation meant they were rarely able to report the serious abuses they experienced.”

The report said that of the hundreds of bodies discovered in mass graves in 2011, some were identified as kidnapped migrants.

In August 2012, the remains of 72 migrants, 14 of them women, were found in a clandestine grave in the San Fernando municipality of Tamaulipas state in northern Mexico. The Mexican government has accused the “Zetas”, a gang whose members formerly served in the military, of carrying out the massacre.

Mexico’s National Commission for Human Rights, CNDH, carried out a survey of migrant abductions from April to September 2010, which found that 11,333 kidnappings took place just in that six-month period. The study covered both foreign nationals and Mexicans heading towards the US.

The principal motive was extortion, the commission said.

"They torture migrants to obtain the phone number of their relatives in their home country or in the US, and once communication has been established with relatives, they indicate under what conditions the transaction must be done to free them," the CNDH report said.

The commission concluded that "government efforts have not been sufficient to reduce the rates of kidnapping”.

Even more worrying than claims of government inaction are the suggestions that officials turn a blind eye to migrant abductions, and may sometimes be involved.

The Mesoamerican Migrant Movement noted that the government’s position is “push the blame onto organised crime, despite numerous charges of [government] complicity, be it direct or by omission”.

For its report, CNDH gathered testimonies from migrants who said local and state-level, staff from the National Institute of Migration, and even railway personnel actively helped criminal gangs to capture migrants.

In a 2010 report on migrants in Mexico, Amnesty International said that “federal and state authorities have consistently failed to investigate abuses against migrants promptly and effectively”.

Mercedes Moreno, whose son José Leónidas Moreno has been missing since 1991, called on newly-elected Mexican president Peña Nieto to prioritise the search for the disappeared.

“What’s happening in Mexico is that [migrants] are being abused; they are being criminalised,” she said.

Officials say new improved legislation will offer much better protection for migrants transiting Mexico. On September 28, a year after a new law on migration was passed, regulations for implementing it were published.

The law decriminalises “undocumented immigration” and abolishes prison sentences for people who carry fake documents or lie about their immigration status. According to parliament’s bulletin, the law "strengthens the safety and security of national and foreign migrants, and recognises them as legal subjects".

Critics say the legislative changes will do little to protect migrants from abuse.

In an interview, Father Tomás González, who runs the LA 72 migrant shelter in Tenosique, in the southern state of Tabasco, described both the law and the regulations as “mediocre”, saying they “focus on national rather than human security”.

“Instead of sealing the borders and attending to US migration policy, they should guarantee human security for the migrants,” he said.

A working group made up of a dozen civil society said that although the regulations did incorporate some recommendations and represented an improvement in some areas, “it does not fully guarantee the human rights of the migrants who travel through and temporarily or permanently reside in Mexico”.

On October 15, the first day in the caravan’s tour, Servelio Mateo was reunited with his mother nine years after leaving his home in Lempira, Honduras. Mateo was found living at Father González’s shelter in Tenosique.

“My son left for the north nine years ago,” his mother Silvia Campos said. “Since then I’ve heard nothing from him. I’ve worn myself out crying for him. Today, I’m crying with happiness in the knowledge that he’s alive. My hopes never died.”

Alexander Robles is a freelance journalist in Mexico.