Ayotzinapa Rural Training College was set up in 1931 in the state of Guerrero, near the city of Iguala. It is one of several rural colleges in Mexico, whose primary objective was to promote social change, and whose classrooms have given rise to various social movements over the decades.

Poverty is the most common condition. The support that Ayotzinapa Training College receives from the government amounts to nothing at all. Each student lives on 35 pesos a day (under $3), though they also help to cultivate crops and rear livestock on the former hacienda’s lands, to meet their basic daily food needs.

Humble origins are always accompanied by generosity. Neighbours of Ayotzinapa frequently count on the students’ support, from help in the fields to rescue during hurricanes. What the students demand for themselves and their community are better living conditions, work opportunities, and that the College continues to exist, for they firmly believe that education is the most valuable route to achievement.

They also denounce injustices that they have suffered at the hands of the state. For example, back in 2012, two students – Jorge Alexis Herrera Pino and Gabriel Echeverría de Jesús – died of gunshot wounds after being caught up in a joint police–army operation on the Autopista del Sol.

The sense of outrage among the students today is stronger than ever, for 43 of their classmates are missing from their homes in Ayotzinapa. The current crisis started on 26 September 2014, when the College’s first-year students were mandated to attend an annual march in Mexico City to commemorate the Tlatelolco Massacre of 2 October 1968, in which hundreds of unarmed Mexicans, mostly student protesters, were gunned down by police and armed forces.

Once the students had requisitioned the necessary number of buses they headed out to the highway to Chipalcingo, but three of the buses lost their way. Official reports, independent investigations and witnesses’ accounts are confused and contradictory, but there is no doubt at all that municipal police patrols blocked the path of the bus cavalcade and opened fire. Aldo Gutiérrez was shot in the head and died; he was the first victim. The surviving students confirm that it was the federal police who fired on and then detained them. They sought shelter, the wounded among them crying out for help, others using their mobile phones to call classmates at Ayotzinapa, calling for immediate assistance.

A second round of firing damaged the buses which should have been on their way to Mexico City. Survivors report that it was again the federal police who fired on and then detained them. A few hours later fellow students arrived from Ayotzinapa and also fell victim. The police recovered the spent bullet casings, and arrested a number of young people at the scene.

On the morning of 27 September there was little mention in the media of the attack mounted on the students, only of the unrest they had supposedly provoked. It was only later that it became known that 43 students had disappeared at the hands of the army and federal police. Among the various versions it was announced that the 43 had been handed over to a criminal gang of drug traffickers – the Guerreros Unidos. From that moment began the Calvary of their family members, who have still not been told of their precise fate.

Just three months before the events at Ayotzinapa, we had learnt of the execution of 22 young people in a bar in the town of Tlatlaya. When the news was broadcast, it was presented in such a way as to look like a military victory over narco-traffickers and members of the Guerreros Unidos. In Esquire magazine Spanish journalist Pablo Ferri published the testimony of a witness to the massacre who related how members of the army had killed the young people. Later on it emerged that three soldiers had opened fire on the young people without the least justification; the three individuals are supposedly to be tried in court for their actions.

Adolescent girls were left widowed mothers when their young husbands died in that Tlatlaya bar.

In Mexico young people are annihilated as if they were a plague.

Since 2005, 38 mass graves have been dug in Guerrero alone.

In everyday speech, to disappear a citizen is commonly referred to as a levantón – slang for a raid or a snatch – a word without legal meaning and which cannot therefore lead to a prosecution. ‘Forced disappearance’ is not deemed a crime in some Mexican jurisdictions, even though it was defined as such in the Rome Statute of the International Criminal Court in 1988.

On 27 January 2015, the former Attorney General of the Republic of Mexico, Jesús Murillo Karam, announced that the students had died; their bodies had been incinerated at a rubbish tip in Cocula, Guerrero; and their ashes had been thrown in the river so as not to leave a trace. He confirmed that the assassins were members of the drug-trafficking gang Guerreros Unidos. Murillo Karam concluded: ‘This is the historical truth.’ Thus he intended to close ‘the Iguala case’ – but widespread indignation was not long in coming.

Three levels of government – municipal, state and federal – have been ineffectual, ambiguous and evasive about the Ayotzinapa cases. The parents themselves have searched for traces of the 43 young people. They have been reinforced by volunteers, journalists and students of numerous other universities, not only in conducting searches but also with the mass demonstrations that have spread through all the main streets and avenues of the country. These spontaneous and passionate protests have been organised on social media and have proved to be a magnificent example of civic consciousness-raising. Across the world there have been demonstrations in 60 capitals demanding to know the whereabouts of the 43 students. Ayotzinapa has spread beyond Guerrero’s borders, and ceased to be the local matter the authorities wish it to be.

Impotence, sadness, pain and rage unite Mexicans marching in the streets of Mexico City and along the main avenues of other Mexican towns, every one bearing the photograph of a college student before them like a shield.

The mother of a student named Julio César Mondragón Fontes suffered such a deep depression that she lost her voice and could scarcely find the strength to declare: ‘To those who administer justice, poor people like us don’t count. Julio César and the other 43 students mean nothing to them, any more than all the families left here to suffer such a barbarity, one we have no means to rectify.’

On Thursday 19 March this year, a group of experts from the Inter-American Commission on Human Rights asked the Mexican government that the Ayotzinapa case be considered as one of forced abduction. Any failure to proscribe it would then become a crime against humanity and the authorities would be obliged to continue the investigation until the whereabouts of the 43 students is uncovered.

The tragedy of Ayotzinapa has highlighted the thousands of cases that have not been investigated. In his essay published in El País on 30 October 2014, Juan Villoro wrote: ‘Mexico is united in indignation and there is an angry clamour for things to change… the Mexico of the armed forces is afraid of those who teach literacy,’ because a literate country is one that can demand and denounce. A literate country can be disobedient. Real students on the marches do not make use of chains, sticks, stones or aggression in order to demand justice. Students act in solidarity, they demand and reclaim what is true, because they know their rights and their responsibilities. According to the Italian journalist Federico Mastrogiovanni, winner of the Mexican PEN Prize in 2015, the massacre in Tlatlaya and the disappearance of the 43 Ayotzinapa students were significant because society (in Mexico and elsewhere) has reacted, as opposed to previous cases when people kept quiet for fear of reprisals.

Many citizens have come out and demonstrated their condemnation. Francisco Toledo, a famous Mexican painter and artist, let loose 43 paper kites bearing the images of the 43 disappeared students in the Zócalo, the main square in Oaxaca. At the Guadalajara Book Fair in December 2014, there was a count-up, repeated four or five times daily, from 1 to 43. A poem by David Huerta, from where the following lines are taken, was read out at every opportunity:

This is the country of graves
Ladies and gentlemen
This the country of howls
This the country of children in flames
This the country of martyred women
This the country that yesterday barely existed
And today doesn’t know where it went.

Find out more about Elena Poniatowska’s novel Leonora.

On 19 May the Euro Caravana 43, representatives of the 43 Mexican students who were kidnapped in Iguala, Guerrero in September 2014, will be in London. View the full programme of events and activities here. If you would like to send a message of support, please do so via cat@englishpen.org.

On Friday 29 May English PEN will host an event to celebrate the publication of Mexico 20 – an anthology of contemporary Mexican writing. Laia Jufresa, Brenda Lozano and Daniel Saldaña París will be in conversation with Maya Jaggi. For more information and to book, click here.