Mexican authorities are probing what led gunmen to attack an SUV in Ciudad Juarez, across the border from El Paso, Texas, killing four people, including two U.S. citizens.
The Chihuahua state attorney general's office said Tuesday the U.S. citizens were from El Paso. Initial reports had 19-year-old Pablo Noe Williams and his mother, 35-year-old Rosa Williams, being from Kansas.
A spokeswoman for the U.S. Consulate in Juarez says officials are working to return their bodies to the U.S.
The others killed were identified as a married couple from Mexico: 24-year-old Alberto Nieto Nieto, and 21-year-old Alma Yesenia Flores.
Officials say the four were in the SUV Friday evening when it was hit by gunfire.
Authorities say they recovered more than 40 assault rifle and handgun shells at the scene.