The decision came after radical teachers attacked the offices of political parties in the southern state of Chiapas, burning the contents, and vowed to block the voting.
The deployment is “aimed at ensuring all Mexicans can go to the polls peacefully,” Mexico’s Interior Department said in a statement. It said troops would be sent particularly to southern states and Oaxaca, where many of the attacks and ballot burnings have occurred.
Violence ahead of the Sunday elections for Congress, governorships and mayorships has already claimed the lives of three candidates, one would-be candidate, and at least a dozen campaign workers or activists.
But unlike the years from 2010 to 2012, when the violence appeared to come largely came from drug cartels, radical movements now appear to pose the greatest threat.
Radical teachers on Friday burned or attacked the offices of five political parties in Tuxtla Gutierrez, the capital of Chiapas. They broke into the offices, ransacked the contents – computers, paperwork and furniture – and burned it in the street.
In the southern state of Guerrero, unidentified assailants tossed an explosive device at the offices of the conservative National Action Party, damaging the windows.
There have been tense moments in recent days as army and police forces faced off with protesters intent on breaking into electoral offices to burn ballots, as they have done in recent days.
“I think this is the worst (election violence) in a lot of ways,” said Jesus Silva-Herzog Marquez of the Monterrey Technological University. “We didn’t have this level of violence even in 1994, when we had elections at the same time as the Zapatista guerrilla conflict.”
The teachers have issued wildly ambitious demands, including 100 percent pay hikes and the end of a constitutionally-mandated teacher evaluation system.