Federal authorities must launch a full investigation into the disappearances of over 40 students in Iguala, southwestern Mexico, as doubts persist that the bodies found in a mass grave at the weekend are theirs, said Amnesty International today.

Sunday’s gruesome discovery of the grave may answer some of the questions over what had happened to the students, who were among a group of 80 leaving the city by bus on 26 September. They were attacked by municipal police and an armed group. Six people were shot dead, more than 20 were wounded and 43 remain missing.

However, only 28 bodies have been uncovered in the mass grave, and they have not yet been identified or established as those of the students.

According to news reports, over 30 people have been detained in connection with the attack, including 22 local police officers.

Erika Guevara Rosas, Americas Director at Amnesty International said:

"Now is the time for President Enrique Peña Nieto to step up and ensure rapid and thorough investigation into these abuses to get to the bottom of what has happened to these victims. It is imperative that Mexico’s promises to respect human rights are not just government platitudes behind which a host of abuses can be committed with impunity.

“The shocking enforced disappearance and killing of students has not occurred in a vacuum. Tragically, this is the latest horrific tale in a series of human rights abuses in Iguala, and throughout Mexico. It is time these horrors stopped once and for all.”

It is also vital that the relatives of the victims are treated with respect and are kept informed ahead of the media of developments in the ongoing search for their loved ones and identification process of the discovered bodies.

Representatives of the Argentine Forensic Anthropology Team, who are in Iguala to help with the investigation, must be given full institutional backing to support the exhumation and identification process. The role of these independent international experts is vital to ensure a reliable process that relatives can trust. The repeated failures in the identification process of human remains in other high-profile human rights cases in Mexico has gravely undermined investigations.

Background

There is chilling precedent for the disappearance of the students in Mexico’s Guerrero state.

In December 2011, the authorities failed to hold federal and state police officials accountable for the killing of two students from the town of Ayotzinapa and the torture and other ill-treatment of 20 others.

In May last year, three people were abducted and murdered. Despite evidence implicating the involvement of the municipal president of Iguala in the killings, the investigation was reportedly closed this May. In both these cases, the federal authorities failed to intervene effectively to ensure justice.

For years, Amnesty has documented and denounced an ongoing pattern of grave human rights violations in Mexico, including disappearances, torture and excessive use of force, as well as impunity.

Last month Amnesty published a report, Out of control: Torture and ill-treatment in Mexico, which noted that reports of torture and ill-treatment at the hands of official authorities had risen by 600 per cent over a decade.

Sixty-four per cent of Mexicans said they were afraid of being tortured if detained by the police or other authorities, according to a survey conducted by Amnesty.