* FBI Lab in Quantico, VA is testing items of interest
* Search volunteers arrived at Dawson Community Church Friday morning
* Search focused solely on Onslow County but officials are following up on all tips
The search is being organized by Team Adam, a program for the National Center for Missing & Exploited Children that provides on-site assistance to law enforcement agencies and families in cases of missing children, according to Onslow County Sheriff Hans Miller.
The search for Mariah has entered its fifth day. Her disappearance Monday prompted an Amber Alert that has gained national attention.
Authorities searching for the missing toddler are asking residents to comb through their properties for anything "out of the ordinary" in the hope that someone will come forward with information that leads them to the little girl.
Volunteers who want to help should be prepared to show an ID to register. Volunteers are asked to wear appropriate attire and bring their own water or snacks.
The FBI said Thursday that it is testing "items of interest" at its lab in Quantico, Virginia.
Onslow County Sheriff Hans Miller is urging the public to comb through their properties meticulously for "any clues," including wooded areas or "outbuildings" such as sheds or barns.
"Our goal is to talk to every person who lives in Mariah's neighborhood," authorities said Thursday. "We have spoken to many of them, but not everyone. Some people may not have been home when we tried to talk to them, we will continue to contact everyone to determine if they have any information that can help us find Mariah."
Dive teams have been searching Southwest Creek in Onslow County, Meador said, which is about 3 miles away from where the family lives.
RELATED: Timeline of events in Mariah Woods' disappearance
Dozens from the shaken community surrounding Mariah's home turned out Wednesday night for a special prayer vigil at Folkstone Original Freewill Baptist Church. Some of the toddler's extended family members are members of the church.
"They're having some rough moments," said Cliff Wilson, Folkstone's pastor. "They're doing all that they can do and they feel helpless. As a small community that we are, we got to all stick together in this."
Earlier Wednesday, the FBI released surveillance photos of a woman and a little girl who matched Mariah's description, in hopes of identifying the pair.
The FBI later said the woman in the picture did not have any connection to their ongoing investigation to find Mariah.
WCTI spoke with a 23-year-old Newport, North Carolina woman Wednesday who said she was the woman pictured in the surveillance photos.
Jetta Long revealed that her daughter was born with a shortened leg, so she said she understood how her little girl could have been mistaken for the missing toddler.
RELATED: I-Team: Strict standards in place to issue Amber Alerts
Mariah Woods' family has said that the 3-year-old struggles to get around on her own and wears leg braces for assistance.
Mariah has been missing since Sunday night when her mother put her to bed.
Woods lives with her mother and her mother's live-in boyfriend on Dawson Cabin Road in Jacksonville, North Carolina.
Her biological father Alex Woods told WCTI 12 Tuesday that he found out his daughter was missing when the Amber Alert was issued and he hasn't seen her for about a year. He said he doesn't believe his daughter was abducted.
WATCH: Raw video of emotional interview with Mariah's biological father
"Someone just walked right up in there, grabbed the 3-year-old out of the bed and she didn't cry, she didn't scream?" Alex Woods said. "Nobody heard anything? Four people in the house, two adults and two kids, someone just comes up and snatches the baby and walks out?"
WATCH: Officials give update on Mariah's case
ABC News reports that her mother reached out to the public in an emotion-filled plea Monday.
"Please, bring her back ... She's my baby, she's my everything," said Kristy Woods in a press conference. "(I) just to be able to touch her and hold her and not let her go again. I'd give anything."
She is described as a white female standing about 2' 9" tall and weighing around 30 pounds. Mariah has brown hair and blue eyes.
The FBI is assisting state and local law enforcement with the investigation; they have brought in the Child Abduction Rapid Deployment for further assistance.
I-Team: Strict standards in place to issue Amber Alerts
Marines based at nearby Camp Lejeune are also assisting in the search.
Authorities said they have been using all means necessary to find Mariah including ground searches assist by a helicopter and K9 units - so far, officials have covered 100 acres.
Officials said more than 225 state and federal personnel are working on the case, adding that they have conducted nearly 100 interviews and followed up on more than 140 leads.
They said no information is too small or insignificant when looking for the missing child. Those with information are asked to call (919) 455-3113.