Young Mexicans are being abducted from poor towns and villages and forced to work for drug gangs, rights groups say, alleging the authorities are failing to do anything to stem the problem.
Stories of young people disappearing, as if swallowed up by the earth, are spreading in parts of Mexico gripped by drug violence which has left some 50,000 dead, according to media counts, in the past five years.
Non-governmental groups in the northern states of Nuevo Leon, whereMonterrey lies, as well as Coahuila and Michoacan, to the west, have documented more than 1,000 disappearances from 2007 to 2011.
But they say they cannot prove that the youths were forced into working for organized crime groups which have rained terror on parts of Mexico as they battle for control of the lucrative multi-billion dollar drug business.
"They tried to take me away around seven months ago," said one 17-year-old in a recorded testimony obtained by AFP from a non-governmental organization.
The youth, who declined to be named, lives in a poor suburb of Monterrey, a flashpoint in Mexico's drug wars where the Zetas gang are fighting a vicious turf war with their former employers, the Gulf cartel.
Armed men forced him into a car one night as he talked to a friend on the street.
"I was frightened, shaking and shaking," the youth said, explaining how he tried to persuade the men to release him by appealing to their religious side, and telling them he had a Bible with him.
He said he was lucky because they finally let him go.
"If you walk the streets after 11:00 pm they abduct you," warned another youth in the same recording, also requesting anonymity.
Requests by AFP to the Mexican attorney general's office for information and a comment on the official numbers of people who have disappeared were not answered.
But a year ago the National Human Rights Commission, a state body, said there had been around 5,000 disappearances since President Felipe Calderonstarted a military crackdown on drug gangs in
Until recently, many believed the ruthless, powerful drug gangs were filling their ranks with volunteers, including ex-soldiers and ex-police, but witness accounts tell a different story.
Youths are "massively being abducted," said Carlos Cruz, an ex-gang member who now heads Citizen Channel, an organization that has rescued almost 4,000 youths from drug gangs since 2003.
Armed men enter marginalized areas and take up to 12-15 young men at a time, Cruz told AFP.
"The majority of those we rescued were co-opted into the gangs because of extreme poverty or because they were taking drugs. But the percentage of those being co-opted has been growing" in past years, he said.
Some were being taken to training camps operated by the Zetas in the northern state of Zacatecas and northwestern Sinaloa and Nayarit, he added.
An Ecuadoran who was the only survivor of a massacre of 72 migrants on a ranch in northeastern Tamaulipas state in August 2010 said the migrants had been killed for refusing to go to work for the Zetas.
Forced recruitment has also been reported in the eastern state of Veracruz, according to migrant activist and priest Alejandro Solalinde.
A young Mexican in jail for involvement in the massacre of 27 farm workers inGuatemala last May said he had been abducted in Veracruz and forced to work for the Zetas, according to Solalinde.
He said he had been told by the governor of Velacruz that it "is the principal state for the forced recruitment" of young people.
Blanca Martinez, director of the Diocesan Center for Human Rights of Coahuila, said missing men in that state were aged an average 29 years old and included engineers, architects and construction workers.
There were attempts to seek a ransom in only a handful of 228 cases documented between 2007 and
2011, she said, calling on officials to start investigating the apparent forced recruitment.
In western Michoacan, families of the missing meet up to exchange information in the state capital Morelia.
Many speak of threats from both criminals and the authorities.
"When you're about to report the crime you start getting phone calls telling you not to whine, that your son will call you in time," said a 55-year-old builder, whose son disappeared with two others in September 2010.