Roberto Muñoz, Wife Cecilia & Their Grandson Armando Salinas Missing After Mexico Trip (VIDEO)

Three members of a Southern California family have been missing for close to a month after taking a trip to Mexico, NBC reports.

Roberto Muñoz, his wife Cecilia and their grandson Armando Salinas went to Mexico to visit relatives over the holidays but shortly after they arrived, their family members lost contact with them.

Relative Delphina Layton expressed frustration that the U.S. Embassy and the FBI have not been much help so far. “I need returned calls,” she said. “Somebody get back to me and tell me that you’re doing something.”

Cellphones belonging to the missing group appear to have been turned off, and border records show that they never crossed back to the U.S., NBC reports.

The missing family, who are from the Coachella Valley, reportedly passed through the infamously violent Mexican city of Ciudad Juarez. Since President Enrique Peña Nieto took office Dec. 1 and the paramilitary group the Zetas moved northward, there is fear that a new wave of killings could sweep Juarez, the Dallas News reports.

Another Southern California family has been missing -- possibly in Mexico -- for about three years. Joseph McStay, 43; his wife, Summer, 46; and their two kids, Gianni, 7, and Joseph Mateo, who would be 6 this month went missing from their home in Fallbrook, Calif. Their abandoned Isuzu Trooper was found four days later, two blocks from the Mexico border.