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Federal agents on Tuesday joined K-9 units and helicopters combing a rural community near the North Carolina coast where a 3-year-old girl vanished after being put to bed.

The disappearance of Mariah Kay Woods prompted a statewide Amber Alert and authorities to search wooded areas in Jacksonville where the family lives, including the grounds of Camp Lejeune, the nearby Marine Corps Base.

"If anybody knows where she is at or any information, just please call the sheriff's department or notify anybody," the girl's mother, Kristy Woods, told reporters Monday through tears. "She is very sweet loving girl."

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The girl's grandmother, Melissa Hunter, said Mariah normally walks with orthopedic braces on both feet and can't step straight without them.

"Every second counts when a child is missing, especially after the cold night we just had," Onslow County Sheriff Hans Miller told reporters on Tuesday. "No piece of information is too small or insignificant," he said, asking for the public's help.

Woods said she last saw her daughter at about 11 p.m. Sunday. An hour later, she said, her live-in boyfriend checked on the toddler again when she woke up, and told her to go back to sleep.

Woods went to check on her the following morning, but alerted authorities at around 6 a.m. when she couldn't find her.

The FBI's Child Abduction Rapid Deployment team, or CARD, was deployed to assist in the search.

The Onslow County Sheriff's Office said they believe Mariah was abducted, and described her as having blond hair and blue eyes and weighing about 30 pounds.

Miller said investigators are asking anyone who had contact with members of the girl's family on Sunday through Monday to contact the sheriff's office.

Family friend Anne Edwards told NBC affiliate WRAL that it would be odd for Mariah to leave the house so easily.

"She's a sweet child, but she is shy with strangers, so she wouldn't just go with a stranger," Edwards said.

Crime Stoppers in Onslow County is offering a $2,500 reward for information that leads to finding the toddler.