Smithfield, N.C. — Local, state and federal investigators continued air and ground searches Monday for a 3-year-old boy who disappeared from a Smithfield flea market Sunday.

Meanwhile, family friends have planned a candlelight vigil for Siraj Munir "Roji" Davenport, for whom state authorities issued an Amber Alert Sunday. The vigil starts at 8 p.m. at Barbour's Grove Park in Four Oaks.

The boy's mother told police she was loading produce at Brightleaf Flea Market into her car and that when she looked up, he was gone. She looked for him for about an hour before calling police, investigators said.

"Every minute that goes by is another minute we don't know where the kid is," Smithfield Police Chief Steve Gillikin said Monday. "We're doing everything we can to find him and looking for a positive ending."

A state Highway Patrol helicopter flew over the area surrounding the flea market Monday and Johnston County sheriff's deputies led a ground search.

Search crews and volunteers also searched Sunday afternoon but suspended the search in the early evening because of weather.

Gillikin said police are following all leads and looking into all possibilities about what might have happened to cause Roji to disappear.

"He'd have never walked away from her," said Tammy Locklear, a close family friend. "He was just well mannered."

"I think it's too early to say it's an abduction," Gillikin said. "I mean the kid disappeared, and there are lots of cases where kids wander off or walk into the woods or different areas."

Anyone who might have seen Roji's or know where he might be should contact Johnston County Emergency Services at 919-934-9411 or call 911 or the state Highway Patrol at *HP on their cellular phones.

"(His mother's) hurting a lot," Locklear said. "I've talked to her several times today and it's just heartbreaking to them and me and others."