State prosecutors said the couple died when their pickup truck was sprayed with bullets. Investigations were underway, but authorities offered no immediate information on the identity of the assailants or a possible motive.

The killings occurred late Wednesday in the town Angamacutiro, Michoacan.

The town government confirmed that the victims were named Rafael Cardona, and his wife, Gloria Ambriz. It identified Cardona as the brother-in-law of the town’s mayor and said the town government’s public Christmas-season events were cancelled.

Local media reported the couple were from Sacramento, California, and were apparently visiting the town.

The town is located on the border with the neighboring state of Guanajuato, which has more homicides than any other state in Mexico. Warring drug gangs fighting for the territory are largely responsible for the violence there.