The Ministry of Public Safety said in a statement, after initially giving a death toll of 20, a cargo truck was found with 16 men shot dead inside, while three others were found dead outside the vehicle.
The events occurred in the municipality of La Concordia, near the border with Guatemala, where violence has been on the rise in recent years.
An initial investigation said the clash was between the Sinaloa cartel, one of the most powerful in Mexico, and another gang identified as the Chiapas and Guatemala cartel.
The ministry said in a statement that the two groups were battling over criminal control of the border area.
According to the non-governmental organization Insight Crime, the region is key for the trafficking of drugs, arms and migrants toward the United States,