An investigation is underway after two Arizona women were found shot to death in an overturned vehicle on a dangerous stretch of highway in northern Mexico.

The women, identified only by their last names and ages, were 72 and 82, the attorney general’s office for the state of Sonora said in a release on social media Friday. 

The victims, originally from Caborca, Mexico, which is further southeast, were dual citizens of the U.S. and Mexico. 

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National Guard soldiers investigating scene

A Mexican National Guard solider and an army solider hold up a sign that says "Mexican Army" in front of a pickup truck with suspected ties to the deaths of two Arizona residents in Sonora, Mexico.  (Attorney General Sonora)

The attorney general’s office said investigators with the Mexican National Guard and the army had found a stolen Ford F-150 and an AK-47 and ammunition believed to be linked to the murders

stolen Ford F-150 found at scene

Investigators found a stolen Ford F-150 believed to be linked to the murders.  (Attorney General Sonora)

"Security forces from three levels of government immediately initiated an operation to locate and arrest the criminal group responsible, with the support of specialized air and ground forces," Sonora state prosecutors said.

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Sonora and the Sonoyta-Caborca highway are known for violence and trafficking of migrants. 

AK-47 and magazines

Investigators also found an AK-47 and ammunition.  (Attorney General's Office in Sonora)

In June 2023, a California student doing horticulture research in Sonora was found shot seven times in an SUV. In December, two U.S. residents and one U.S. citizen were shot at by gunmen while traveling a highway in Sonora. One of the men was killed, according to the Arizona Daily Star. 

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The state was once controlled by infamous drug lord Joaquin "El Chapo" Guzman, who was arrested in 2016 and is serving a life sentence in Colorado, and three cartels continue to war in Sonora. 

The U.S. State Department did not immediately respond to Fox News Digital’s request for comment.