A Mexican teacher protest against neoliberal education policies turned deadly on Sunday, with nine people killed, after police unleashed gunfire on the demonstrators' road blockade.

According to TeleSUR, teachers from the dissident union, Coordinadora Nacional de Trabajadores de la Educación (CNTE), "had set up the blockade as part of protests over an education reform implemented by President Enrique Peña Nieto and the arrest of several of the unions' leaders over the past week," which they said, were politically motivated.

With scant reporting, much of the details of the have emerged on social media, including reports that police attacked an elementary school being used as a makeshift clinic to treat the more than 100 wounded.

Quick recap: six killed by police including two teachers, burning barricades and the people are still resisting. pic.twitter.com/vZn6YaiC8X

— Dirty Thirty Tony (@MexicAnarchist) June 20, 2016

Just to give y'all a scale of what's been going on in Oaxaca. pic.twitter.com/cKjJdj0CTQ

— Dirty Thirty Tony (@MexicAnarchist) June 20, 2016

Police denied that the original shots were fired by them. "Mexico's National Security Commission originally said in a statement that the police officers involved in the operation near the town of Nochixtlan were not carrying guns," BBC reports. "But federal police chief Enrique Galindo later said that an armed unit was deployed after shots were fired at the police and the protesters by 'unidentified people' not linked to the demonstration."

However, national security commissioner Renato Sales Heredia warned last week that the government would employ a "moderate use of force" to repress the ongoing mobilization.

TeleSUR further reports: "Another clash between demonstrators and police took place in the city port of Salina Cruz, in Oaxaca as well, where another group of teachers were blockading a road that connects the state with its neighbors on the Pacific coast. Local media also reported dozens of injured protesting teachers and dozens of arrests, however authorities have not said anything on this case."

Blockades were erected across Oaxaca in recent days and on Friday thousands of teachers marched in Mexico City to protest the controversial reforms.

Thousands in Mexico City chanting for the president to leave. Teachers & their supporters get greeted with riot cops https://t.co/avIAJPHRwK

— Dirty Thirty Tony (@MexicAnarchist) June 18, 2016

During that demonstration, activists read a letter that was signed by hundreds of global academic, religious, popular, student, human and social rights organizations condemning the "brutal repression" exerted against teachers.

"We think that the authorities must commit to dialogue, recognizing the just demands of the teachers' movement, and not to force to solve this and any other conflict, especially in a country marked by violence and impunity," the letter states.

The union—which was founded to represent teachers in the poorer and largely indigenous southern states of Mexico—is fighting against the government's 2013 education reform that imposes teacher evaluations. They say the mandatory testing is being used to justify mass layoffs and fails to consider the specific challenges of teaching in rural areas and Indigenous communities.

"In many places, educators are expected by the population to do more than provide classes in schools lacking computers or basic supplies such as chalk," Vice News explains.