NOGALES - Authorities investigating the disappearance of Isabel Celis have said they haven't ruled anything out in her disappearance and that includes their search efforts along the southern border.

At the Dennis DeConcini Port of Entry in Nogales, Customs and Border Protection officers are keeping the missing six-year-old in mind as they observe southbound traffic, "all of our officers are aware of the situation and they're making every effort to look for her," said Juan Osorio, a spokesman for the agency.

Flyers with the little girl's face were shown to officers beginning on Saturday and are prominently displayed at the port, "there's always the possibility of people being taken out of the country at the northern/southern border airport or seaport," Osorio explained.

Jim Hill and his brother Mike Brevik, from Tombstone, saw flyers posted in Nogales, Sonora, "I saw actually a little kid with flyers handing them out to the cab drivers," Hill said.

Isabel's picture and reward information are also posted on shops along Morley Avenue near the pedestrian port of entry, "it's just a really sad situation but I'm glad to see that people on both sides are literally stepping up on this one," Hill said.