The attack occurred late Sunday near the town of Zinapecuaro, Michoacan. The dead include 16 men and three women and several wounded people in the attack. The office said that drug cartels and gangs had been fighting in the area.
Michoacan has been the scene of a longstanding turf battle between local cartels and the Jalisco cartel from the neighboring state of Jalisco.
The fighting has included bomb-dropping drones, landmines, and homemade armored cars.
While illegal in many areas, Cockfighting remains a popular pastime in parts of Mexico, though the fights between roosters are usually held clandestinely.
