(CBS/AP) TUCSON, Ariz. - The family of an Arizona girl who went missing from her bedroom over the weekend said they will never give up looking for 6-year-old Isabel Mercedes Celis.
"We appreciate everyone's interest in finding our daughter, Isabel, and thank all the volunteers who have come out to search for her," the family said in a statement Monday evening. "We love Isabel and will never give up finding her."
Tucson police are now trying to determine what happened to Isabel. Her parents say they awoke Saturday to find her missing. Police reported a window was open with the screen pushed inside.
Since her disappearance, investigators and search volunteers fanned across Isabel's neighborhood and an area landfill searching for clues.
Volunteers posted fliers with a photo of Isabel - about 4 feet tall - with brown hair and hazel eyes.
Her parents, Becky and Sergio Celis, told police they last saw their daughter at 11 p.m. Friday. Her mother was at work Saturday when her father went to wake her at 8 a.m. and discovered her missing, police said.
Authorities call the case a "suspicious disappearance/possible abduction."
"We're not ruling anything out of the investigation at this point because we really need to keep our mind open about all the information that's been brought to us," Police Chief Roberto Villasenor said.
Officers have been interviewing sex offenders in the area. This is a practice that has become standard in all abduction investigations.
On Monday, FBI dogs - one that can find human remains and the other used for search and rescue - went through the family's home and turned up information that required a follow-up, but police declined to say what that was.
The family said in the statement that they are fully cooperating with authorities.
Experts say abduction from the home is relatively rare, with just over 18 children taken each year.
"It's unusual, but it's not unprecedented," said Ernie Allen, president of the National Center for Missing and Exploited Children, which is involved in the search.
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