The Veracruz state prosecutor's office said yesterday that firearms had been used in the confrontation.
Mexico's labor department said the dispute involved supporters of rival factions of the union at the plant on the outskirts of the port city of Veracruz. The dispute has been going on for at least five years.
Mexico's antiquated labor laws do not provide clear and agile methods to determine who represents workers at a given factory.
Disclaimer: No Business Standard Journalist was involved in creation of this content