Two Arizona women were killed when gunmen opened fire on their vehicle in the northern Mexican state of Sonora Friday morning, Mexican authorities said.

The victims, ages 72 and 82 and originally from the Sonora city of Caborca, were found dead in an overturned, bullet-ridden white Nissan Pathfinder at about 10:30 a.m. on the Sonoyta-Caborca highway, the Sonora attorney general’s office said in a news release.

Mexican authorities conducted a search and located a vehicle believed to be linked to the suspects and described as a stolen Ford F150; it was found abandoned in the Sonora town of Quitovac. In the vehicle, the authorities found four firearms, dozens of cartridges of ammunition and bulletproof vests, the attorney general’s office said.

Officials did not immediately provide a motive for the attack, although Sonora has seen several incidents of cartel violence in recent years. 

In June 2023, a Ph.D. student from California was found dead in an SUV in Sonora, shot seven times, after going missing when he drove across the border to conduct horticulture research. 

In March, Sonora prosecutors said seven bodies were found near the town of Puerto Peñasco, on the Gulf of California. The victims were all men wearing military-style gear, and had all been shot to death.