According to state government report, the fight broke out at approximately 2:30 P.M. (local time) at the Regional Center for Social Reintegration in the town of Cieneguillas, located on the western flank of state capital Zacatecas, the state government said in a statement issued on Tuesday evening.
The report said an inmate was arrested by the prison forces after an inmate was found with a firearm. Another three guns were found in the prison, as well as a number of knives.
The Mexican authorities said they have launched an investigation to determine those responsible for the fight and how the weapons entered the prison, according to the statement. Security will be boosted at prisons in the state after the fight, the government said.
The authorities did not say how the fight started, but several Mexican news outlets reported that inmates from rival cartels had turned a dispute over a friendly soccer game into a deadly fight.
Mexican prisons have long been plagued by violence. In 2017, at least 28 inmates were killed when a brutal fight broke out in a prison in the Mexican Pacific resort of Acapulco.