TUCSON, Ariz. (AP) -- The parents of a missing 6-year-old Arizona girl asked their parish priest for prayers Sunday as volunteers passed out fliers across Tucson and more than 150 law enforcement officers tried to figure out whether she had been abducted.
Tucson police chief Roberto Villasenor said at an afternoon news conference that officers working the case had served at least two search warrants but had no new clues in the disappearance of first-grader Isabel Mercedes Celis.
He said the girl's parents, identified by friends as Becky and Sergio Celis, were helpful as police worked to find their youngest child. He said police were still classifying the case as 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 said. "The family has been cooperating with us."
Officers kept the whole neighborhood block where Isabel lives cordoned off for a second day and fanned out over a wide area looking for clues to the possible kidnapping.
The Celises last saw their daughter in her bedroom at their Tucson home at 11 p.m. Friday and discovered her missing at about 8 a.m. Saturday, police spokeswoman Sgt. Maria Hawke said. The parents phoned 911 minutes later.
Mary Littlehorn, who has worked with Becky Celis as a registered nurse at Tucson Medical Center for five years, said the couple has been together since they were teenagers and doted on their sons and daughter. She said Isabel, whose nickname is Isa, loved to play baseball and dance; the girl was supposed to play in a baseball game Saturday.
"She's just the sweetest, she is feisty, she's full of life and spirit," Littlehorn said.
Littlehorn, who gathered Sunday with other family friends at a police command post, said authorities separated the two parents for hours Saturday as they questioned them. She said it was difficult for them knowing their little girl was out there somewhere.
"She hasn't been allowed to help look for her daughter," Littlehorn said of Becky Celis.
She said she's spent a lot of time with the family, visited with them in their home and their families shared babysitting responsibilities. She said Becky Celis is a registered nurse in the pediatrics unit and Sergio Celis is a dental hygienist.
She said there's no way anyone in the family is involved in the disappearance.
"We all feel this is somebody who's been watching Isa for some amount of time to know where her bedroom is," Littlehorn said.
At St. Joseph Parish on Sunday morning, the parents and their two sons attended an early Mass, and deacon Leon Mazza described the parents as "very upset."
"We didn't ask for any information. We just let them know if they need help, come see us," Mazza said.
Parish priest Miguel Mariano said the family regularly attends Mass and said he asked the parents if they needed any help from the congregation. "And then they said, 'No, Father, just prayers,'" Mariano said.
The couple hurried off, saying they were going to meet with police.
The Catholic church and its school are just down the street from the family's home, and Mariano said in his sermon that he hoped whoever has Isabel has a change of heart.
"I feel, in the name of the community, we feel we are violated," he said later.
Investigators were looking into various scenarios, including the possibility Isabel wandered out of the home she shares with her parents and two brothers. Hawke said Sunday the wandering off theory was becoming less likely as time passed.
Karen Hebert, another registered nurse, said Sunday that she has worked with the girl's mother for the past six months. Hebert, with help from her dog, planned to help with the search.
"She talks very highly about her kids, how smart they are, how playful they are. She just lights up and smiles when she's talking about them," Hebert said. "With all the hurt I'm feeling, I can't imagine what they're going through."
After a fruitless day of searching Saturday, numerous patrol and search and rescue personnel continued the hunt Sunday morning, Hawke said. She said that at any given time, 75 to 100 officers were taking part, including police, FBI agents and deputy U.S. marshals.
Teams combed a large swath of Tucson on Saturday into the evening using street patrols, dogs and a helicopter. At one point late Saturday, communications operator Patrick Olea said the area encompassed "pretty much the entire east side."
The girl's home is situated in a working-class neighborhood, sandwiched between a shopping mall to the east and businesses and the Catholic school and church to the west.
Police were keeping anyone but residents out of the neighborhood on Sunday. A home on the street of small, older single-family brick homes was surrounded by yellow police tape, while a group of people outside one home talked with a police officer.
Volunteers were manning an outpost set up near the family home as others, many family and friends, fanned out across the city for a second day. They were posting fliers of the girl -- who is described as about 4-feet-tall with brown hair and hazel eyes -- in gas stations, malls and fast food restaurants that included a photo of Isabel holding up a school achievement award.