A Mexican teachers' strike that began two months ago turned violent this week, with rebel "maestros" looting, burning and partially destroying the offices of Mexico's three main political parties in Chilpancingo, the capital of Guerrero state.
The looting started after a peaceful march in which teachers had gone to the Guerrero State Assembly to protest a local law, that reinforces the Mexican President's plans for education reform.
President Enrique Peña Nieto wants to improve Mexico's weak education system by obliging teachers in Guerrero and elsewhere to take standardized tests in order to keep their jobs. His national education law would also put the government in charge of hiring teachers, a process that is currently controlled by teachers unions.
But such mild proposals have been met with fierce resistance in Guerrero, where more than 300 schools have been shut down for two months already, leaving more than 25,000 students without classes.
A highway that links Mexico City with the tourist resort of Acapulco -- located in Guerrero -- has already been blocked three times by protesting teachers who want the president's education reform plan to be changed. Protests have also spread to neighboring states like Oaxaca, and Michoacán, where teachers blocked another highway this week and temporarily took control of two fuel trucks that belong to the national oil company Pemex.
So why such drama over a law that talks mainly about standardized tests, and modernizing hiring practices?
Here's the teachers' side of the story
Teachers' unions in the south of Mexico say that it doesn't make sense to evaluate every teacher in the country with the same test, because teachers in the poor areas of Mexico have far less resources to work with in the first place.
These groups argue, for example, that you can't expect a teacher in a rural area of Oaxaca, who has to teach several levels of elementary school by him or herself, and must sometimes walk long distances to schools in remote areas, to pass the same test that is given to a teacher from Mexico City, who has more access to education opportunities, and gets to work with a more uniform group of students.
Firing teachers from rural areas because they do not perform as well as those from urban areas, would be totally illogical, according to unions in the south of Mexico.
Another criticism of the education law, is that it does not do enough to change conditions in Mexican schools, and is serving just as an excuse for the federal government to take over the process of hiring of teachers, which is currently controlled by unions.
"The reform really is an effort to wrest control of the system away from the union and put it back in the government's hands. The legislation says nothing about budgets, curricula, classroom size or learning methods," Mexican journalist Carlos Puig writes in an oped recently published by the New York Times.
This is the government's argument
Supporters of the education law point out that it is necessary to stop unions from controlling how teachers are hired, because this system has led to a series of corrupt practices.
One problem that commonly occurs in Mexico for example, is that union leaders "sell" jobs to aspiring teachers who have no other way of breaking into teaching other than by paying off large sums of money.
A recent article by Reuters points out for example, that a secondary school teacher in Mexico City paid $23,000 for a lifelong position, which she acquired from a retiring teacher, who then paid the union for the job to be transferred.
Union control over the teacher hiring process currently makes it almost impossible for the Mexican government to fire teachers who underperform. Education NGOs also claim that unions are using state funds set aside for education to pay off thousands of employees who hold office jobs and conduct no teaching duties whatsoever.
Supporters of the Mexican government say that the new education law would eliminate such practices by creating a national merit based system for hiring teachers, which would be monitored by the federal government.
The education law would also improve standards by allowing the government to fire teachers who do not pass standardized tests.
However, implementing this part of the law could be challenging, as recent testing efforts suggest that a great number of teachers would fail these tests.
In arecent test which was administered to 264,000 primary school teachers by Mexico's Education Ministry for example, 38% of the country's teachers scored so low, that the government said these teachers required "immediate attention." In other words, they failed the test.
What happens next?
The main framework for Mexico's education reform was approved earlier this year, and Mexican President Enrique Pena Nieto has said that it will not go through any major changes, despite the disruptive protests in Guerrero.
What is being discussed now are the details of how the law will be implemented, with congress looking over things like how standardized tests will be administered, and how the new hiring process for teachers will work.
Teachers unions might be able to have some input in this debate. In Oaxaca for example, the local branch of the National Education Worker's Union has received some support from the local governor, who has sent an alternate education reform proposal to the Mexican Congress, that suggests making tests different for the poorer southern Mexican states.