Updated

MEXICO CITY (AP) — U.S. officials confirmed Monday that an American citizen was found dead in northern Mexico.

The U.S. Embassy said the body of Ronald C. Ryan was recovered in Sonora state, across from Arizona, but gave no other details.

Jose Larrinaga, spokesman for Sonora state prosecutors, told reporters Sunday that Ryan's body was found the previous day partially buried near a creek on the outskirts of Santa Ana, a city 60 miles south of Nogales, Arizona. A cause of death had not been determined and the body was taken to the border city of Nogales, Mexico, for an autopsy, he said.

Larrinaga said Ryan, 67, of Phoenix, Arizona, had been reported missing May 3.

State police had reported detaining three men the following day who had left Ryan's pickup truck at a carwash in Santa Ana. Officers seized several automatic rifles, dozens of bullets and marijuana from the men, ages 18, 20 and 21, state police said.

Local media said two of the men are the son and a nephew of Jose Vasquez Villagrana, an alleged key operator of the Sinaloa cartel who was arrested in February.