On 20 June last year, Alejandro Jose Penata Lopez disappeared after leaving the school where he worked in the region of Cordoba in northern Colombia. His body was found in a nearby village. He had been tortured and then hanged with barbed wire.
It is a shocking case, but Penata Lopez was the 20th teacher to be murdered in the Cordoba region in under three years and the fourth of seven to lose their lives in 2011. A month after his death, a local school of more than 1,000 children suspended classes when its 44 teachers fled their homes. The teachers had received an ultimatum: they had one week to each pay 15 million pesos (approximately pound;5,000) to a paramilitary group operating in the area. If they did not, they had to leave the area or they would be killed.
According to the Cordoba teachers' association, Ademacor, 107 teachers have reported receiving threats from the armed groups and criminal gangs that plague the region. The union says many teachers have abandoned their jobs, leaving nearly 4,000 children facing the prospect of being unable to finish the school year. Others have continued to teach classes but under police protection.
Jorge Bruno Barrios, secretary general of Ademacor, said: "Teaching in Cordoba, we are living in a state of anxiety where we are scared to go to work."
Neo-paramilitary organisations and criminal gangs are competing to fill the vacuum left by the demobilisation of the United Self-Defence Forces of Colombia (AUC), the drug-trafficking, right-wing paramilitary group that for years terrorised teachers it accused of collaboration with Colombia's leftist guerrilla insurgencies. Colombia's main guerrilla groups, FARC and ELN, also operate in the area.
In the AUC era, paramilitaries targeted teachers who showed the slightest sign of dissent: community organising, speaking out on social issues or belonging to a union. While teachers are often still targeted for their union activities, many more are the victims of plain extortion.
The perpetrators are almost never caught. According to Mr Barrios, "(Cordoba) is a department where people are murdered, killed and extorted every day and what you see is that impunity reigns."
The situation has become so desperate that Ademacor is calling for schools to be designated "Peace Territories", free of all armed groups, legal or illegal. "We want guarantees that everyone in Cordoba, from whichever illegal group or the authorities, respects educational institutions," said Mr Barrios.
Teachers in the area have staged strikes to draw attention to the danger they face and Ademacor has helped to organise marches for peace that have brought together more than 10,000 teachers, students and workers.
"What we are looking for is to bring the best teaching possible," said Mr Barrios. "Not from a base of fear and intimidation, but from a base of democracy (and) plurality, towards a transformation of society that results in social peace."