MICHOACÁN, Mexico (ValleyCentral) — Federal authorities are investigating a shooting that left 20 people dead and others injured at a cockfighting venue near the town of Zinapécuaro.

The shooting occurred around 10:30 p.m. on Sunday at a venue used for illegal betting on cockfights in the town of Las Tinajas, located just outside of Zinapécuaro, according to a statement by the Fiscalía General del Estado de Michoacán (FGE).

Authorities say 17 men and three women died in the shooting with at least five more being transported to the hospital. The cause of the shooting has not been determined, however, police have labeled the shooting an attack and are continuing to search for those responsible.

Investigators have located more than 100 shell casings from different parts of the venue and have seized 15 vehicles at the site to search for information.

Michoacán is one of Mexico’s most dangerous states for gang crimes. The Western Mexican state is one of five states that the United States advises Americans not to travel to due to “crime and kidnapping.”

On March 10, Cesar Valencia Caballero, mayor of the small town of Aguililla, was murdered by undetermined forces just weeks after military forces entered the town to ward off gang activity.

Aguililla, a municipality of about 15 thousand deep in Michoacán’s mountainous avocado-growing terrain, came under siege by the Jalisco New Generation Cartel (CJNG) in 2021.

Nemesio Oseguera Cervantes, the leader of CJNG, is from Aguililla. CJNG is regarded as one of the most dangerous drug cartels in the world.

U.S. imports of avocados from Mexico temporarily halted in February after a U.S. plant safety inspector in Mexico stated they received a threatening message. Mexico accounts for 80 percent of the United States’s avocado imports with roughly 92 percent of Mexico’s avocados grown in Michoacán.

The Mexican National Guard rolled through the town in February in an attempt to restore order to the area and forced the cartel to flee from the town.