Gunmen on Wednesday killed six police officers in a northern Mexican state where rival cartels are fighting over drug trafficking routes, authorities said.
Five of the officers were shot dead while training at a sports center in Calera de Victor Rosales, the Zacatecas state government said.
Zacatecas Governor David Monreal condemned what he called a "cowardly attack" and offered his condolences to the family, friends and colleagues of the victims.
Violence has spiked in recent years in Zacatecas, with experts citing a turf war between the Sinaloa and the Jalisco New Generation cartels for control of lucrative drug smuggling routes to the United States.
In January, 10 bodies were found in a sports utility vehicle abandoned in front of the governor's palace in the Zacatecas state capital.
Across the country, more than 340,000 people have been killed in a wave of bloodshed since the government deployed the army to fight drug cartels in 2006.