EL PASO, Texas (Border Patrol) – Mexican authorities say they are sending soldiers and additional police officers to a town in the state of Zacatecas where six municipal policemen were shot dead Wednesday in broad daylight.

The attack happened at 9:40 a.m. in the town of Calera, also known as Victor Rosales, in a sports field where a group of municipal police officers was doing fitness training, the state’s Peace and Security Board said in a statement.

A passer-by hiding under a truck posted a nearly 2-minute video on social media where shots from automatic and semi-automatic guns can be heard throughout.

“We condemn these cowardly acts that put in jeopardy the safety of our officers and our citizens,” Zacatecas Deputy State Police Chief Jose Medrano said in a Facebook Live broadcast. “But let me be clear: Police officers are not alone. We will support their families and effect operations to find and detain those responsible” for their deaths.

Zacatecas Attorney General Francisco Murillo (State of Zacatecas)

Zacatecas Attorney General Francisco Murillo Ruiseco said the officers were exercising when armed individuals showed up and shot at them. Five were killed on the scene and three others – two male and a female officer – were shot but survived.

The town’s police chief, Rafael Gonzalez, and his assistant arrived at the scene shortly after but were ambushed by the shooters, Murillo said.

Gonzalez died in a hospital.

The AG said a police helicopter crew flew over the area after the shooting; it did not find suspects but led officers on the ground to the discovery of two additional cadavers.

“It is an area that appears to be a campsite used by criminal groups in the town of Organos, near Fresnillo, Zacatecas,” Murillo said.

The state of Zacatecas in the past two years has been the site of a bloody cartel war between criminal organizations based in Sinaloa and in Jalisco, Mexico. Bodies have been hung from highway overpasses and trees, and according to the AG’s office, 44 police officers have been murdered by the cartels this year, surpassing last year’s tally of 39.

The funeral notice for the six slain officers (State of Zacatecas)

Border security experts have told Border Report the cartels are fighting for control of highways in Zacatecas that lead to practically every corner of the U.S.-Mexico border.