Dozens of people were abducted and killed by Mexican security forces over the past six years, according to a new report from Human Rights Watch.
The report, released on Wednesday, said that the disappearances of 149 people, many of them civilians, followed a pattern in which security forces detained them without warrants at checkpoints, homes or workplaces, or in public.
When families ask about their relatives, security forces deny that they were detained, or urge family members to look at police stations or army bases.
The group criticised former president Felipe Calderon for ignoring the problem, calling it "the most severe crisis of enforced disappearances in Latin America in decades."
The report was a grim reminder of the dark side of the war on drug cartels that killed an estimated 70,000 people during Calderon's six-year presidency. Enrique Pena Nieto, Mexico's current president, has pledged to take a different approach and focus on reducing violent crime and extortion rather than attacking the cartels directly.
A culture of impunity
The government last month introduced a long-delayed law to track victims of the drug war and compensate the families, and says it is moving ahead with plans to roll out a genetic database to track victims.
"There exists, in theory, a database with more than 27,000 people on it," said Lia Limon, deputy secretary of human rights at Mexico's interior ministry. "It's a job that's beginning."
Still, impunity remains rife: The armed forces opened nearly 5,000 investigations into criminal wrongdoing between 2007 and 2012, but only 38 ended in sentencing, according to Human Rights Watch.
Last year, a civic group released a database which it said contained official information on more than 20,000 people who had gone missing in Mexico over the past six years.
The group, Propuesta Civica (Civic Proposal), said the information was collected by the federal attorney general's office while Calderon was in office. The missing include police officers, labourers, housewives, solicitors, students, businessmen and more than 1,200 children under the age of 11.
They are listed one by one with such details as name, age, gender and the date and place where the person disappeared.
Among the examples cited by Human Rights Watch is evidence suggesting that marines detained about 20 people in three northern border states in June and July of 2011. Though it denied abducting the victims, the navy later acknowledged it had contact with some before they disappeared.