NEAR BRUNSWICK, Ga. -- Nearly four days without any trace of Christopher Barrios Jr., Glynn County police are focused on the possibility that the 6-year-old was abducted, while volunteers continue to comb nearby neighborhoods and woods.

Christopher was last seen about 6:30 p.m. Thursday near his grandmother's home in the Canal Mobile Home Park. Nearly 300 volunteers spent the weekend searching the area, and organizers say their efforts will continue from 8 a.m. to 6 p.m. until Christopher is found.

After two days of searching with ground units, helicopters, K-9 officers, mounted patrols and ATVs, the police said they are convinced Christopher is no longer in the area.

"We're satisfied right now that anything that could've been done has been done," said Glynn County Police Department Chief Matt Doering.

Although police have no physical evidence that Christopher was abducted, police said they are increasingly convinced that he was taken.

"If this guy's out there listening, or will listen ... that one word or that one expression of concern, whatever it may be, just drop him off somewhere," Doering told Channel 4's Dan Leveton on Monday.

Police said they are trying to identify fingerprints found on a toy Christopher was carrying Thursday night.

On Monday, the Georgia Bureau of Investigation issued a Levi's Call -- Georgia's equivalent to an Amber Alert.

GBI spokesman John Bankhead said Levi's Calls are mostly used for confirmed abductions but "given the scenario, we felt it was best to go ahead and issue one."

After having the police stationed in the neighborhood for nearly two days, Christopher's aunt, Julie Haymans, said that not having them around any more is hitting the family hard.

"You feel hopeless. Very empty like a stomach ache," Haymans said. "I think calling off the search was like everyone had given up and that was what upset them the most."

But not everyone gave up. Teams of 20 volunteers were out Monday to continue to search for the missing boy.

"We know the officers did all they could do, but being a civilian of the community you're thinking he's out there somewhere still," said searcher Amy Embery.

And the family appreciates every effort made toward finding their child.

"It's like you have five fingers and one of them gets chopped off, Christopher is my fifth finger and until he comes back I have four," said Christopher's grandmother, Sue Rodriguez.

Christopher Barrios, Jr., was last seen wearing a blue-green pullover sweater with black pants and white Reebok tennis shoes.

A $30,000 reward is being offered for his safe return.

The Glynn County Police Department asks anyone who has seen Christopher or can provide further information to call 912-554-7803 or Silent Witness at 912-264-1333.