Police are scaling back search efforts for a 6-year-old girl who was last seen Friday night when she was getting ready for bed in her Tucson home.

"It still has a search component to it," Tucson Police Chief Roberto Villasenor said at a Wednesday morning press conference. "But mostly, what I would consider this now is just the investigation into a missing child."

Officials expected to wrap up their intensive search for Isabel Mercedes Celis by Wednesday morning.

"Obviously, I'm disappointed that we haven't found her at this point. But that doesn't mean we're giving up hope or that we're not going to continue to use all the resources that we need to try and find her and follow up on these leads," Villasenor said.

The FBI has also brought in specially trained profilers to help in the search.

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More than 20 officers had worked through Tuesday night in the neighborhood surrounding Isabel's home, Villasenor said. That's a sharp reduction from the 150 officers from various agencies who first took part in the search.

Villasenor said the drop in personnel doesn't mean authorities have given up hope of finding Isabel alive.

He said police will be shifting from searching to an investigative phase, since investigators have re-visited sites they believe could be relevant.

About 50 officers finished searching a city landfill, but Villasenor would not disclose if any leads were found. Authorities had said the landfill search was conducted because trash had been taken out Saturday before police could secure the home.

Authorities said they were following more than 260 tips in the case.

Investigators have kept Isabel's family away from the home as they search for clues to her disappearance from her bedroom.

On Monday, FBI dogs -- one that can find human remains and the other used for search and rescue -- went through the home and turned up information that required a follow-up, but police declined to say what that was.

Investigators from the FBI were going through the home again Tuesday, and the family had not returned, said Lt. Matt Ronstadt, a Tucson police spokesman.

Since Saturday, investigators and volunteers have fanned across the neighborhood searching for clues. Volunteers posted fliers with a photo of Isabel -- about 4 feet tall with brown hair and hazel eyes -- holding a school award.

Her parents, identified by friends as Becky and Sergio Celis, told investigators they last saw the first-grader at 11 p.m. Friday. Her mother, a nurse, was at work Saturday when her father went to wake her at 8 a.m. and discovered her missing, police said.

Police 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," Villasenor has said.

He said at a briefing Tuesday that the National Center for Missing & Exploited Children, which has been assisting investigators, now considers Isabel's disappearance the highest-profile case in the nation right now.

The Pima County attorney's office is offering a $6,000 reward, which includes an anonymous donation of $5,000.

The Associated press contributed to this report.

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