SAN DIEGO -- An operation involving many of the same people who looked for Danielle van Dam continued Monday as law enforcement personnel and volunteers searched for a toddler who police believe was abducted from Balboa Park.

MISSING JAHI TURNER Light-Skinned African-American 30 pounds, 30" tall Black hair Wearing blue long-sleeved "Winnie the Pooh" T-shirt, blue nylon pants with an orange drawstring, and gray tennis shoes INFORMATION Tip Hotline: (619) 531-2000 Volunteers: (619) 744-9521 Download A Missing Flyer SOUND OFF Share Your Thoughts VIDEO Hear From Volunteer Who Found Danielle Case Upgraded To Abduction Reaction From Boy's Family

On Saturday, Danielle's parents, Damon and Brenda van Dam, lent their support to the search for 2-year-old Jahi Turner, showing up at Balboa Park to encourage others to join the effort.

Jahi has been missing since Thursday afternoon. His stepfather told authorities he left the boy at Balboa Park to play with two children -- who appeared to be under the care of a woman -- while he got a soda at a nearby vending machine, police said.

When Tieray Jones, 23, returned 15 minutes later, he said his stepson was gone. So, too, were the woman and children.

"Detectives continue to process leads, but we have not located Jahi and we do not have a suspect or suspects in his disappearance," said Dave Cohen of the San Diego Police Department.

Investigators are also looking for the woman Jones said he saw with the children shortly before Jahi's disappearance. Police released a sketch of her (pictured, right) over the weekend.

The woman was described as white, with a tight ponytail. The children who appeared to be with her may be between 2 and 4 years old, the SDPD representative said.

"She is not a suspect, but we believe that she may one of the only people who can tell us definitively what happened to Jahi," Cohen said.

Dozens of officers from the SDPD and other agencies have been combing the city's historic downtown open-space preserve near 28th and Beech streets, along with surrounding canyons and neighborhoods, searching for Jahi.

Search-dog teams also have fanned out in the area, one of them leading a specially trained law enforcement bloodhound from Riverside County. Aiding in the operation have been FBI, Navy and sheriff's personnel.

It's the most extensive local missing-child search since Sabre Springs second-grader Danielle van Dam was kidnapped three months ago. That hunt ended when her body was found along an East County road more than three weeks later. The girl's neighbor, 50-year-old David Westerfield, is facing murder charges for allegedly kidnapping and killing Danielle.

Detectives led the boy's stepfather (pictured, left) through the park Friday, having him retrace the steps he said he took in the minutes before Jahi went missing.

In response to a question, Cohen said officials had "no reason at this point not to believe (Jones') account."

Police encouraged the same level of public awareness about Jahi's disappearance as that generated by Danielle's kidnapping.

"What we are asking people to do at this point is to be aware of the child's picture," Cohen said, referring to snapshots that have been widely disseminated by news media. "If you see anything, please give us a call."

Local resident Bill Garcia coordinated volunteer searches, and about 120 people have volunteered to search over the weekend. Garcia's command post is at Moose Lodge 508 at 1648 30th St., Cohen said.

Jahi is described as a light-skinned African-American, about 30 inches tall and weighing 30 pounds.

At the time of his disappearance, Jahi he was wearing a blue long-sleeve T-shirt with a "Winnie the Pooh" cartoon character on it, blue nylon pants with an orange drawstring and gray tennis shoes, police said.

"We simply can no longer conclude that this 2-year-old boy walked away and simply has not been found," Cohen said. "We believe somebody has taken him away."

Jahi's biological father lives in Maryland and was recently released from "jail or prison" in that state following a conviction on an unknown offense, Cohen said.

Police have spoken with him and "do not believe that he is any way involved in this," the SDPD official added.

The child's mother, Tameka Jones (pictured, left), 18, is in the Navy. She left Monday for a week of maneuvers aboard the dock-landing ship Rushmore.

The missing boy reportedly had been living in Maryland until last week, when his mother took him to San Diego before shipping out to sea.

Upon hearing about her son's disappearance, the woman's commanders put her on a small boat for San Diego. Since arriving back on shore, she and Jones have been "extremely cooperative," Cohen said.

Officials urged anyone with information in the case to call San Diego County Crime Stoppers' anonymous tip line at (619) 235-8477 or SDPD communications at (619) 531-2000.

Pictures and information about the missing child are also available at the Web site DanielleMissing.tripod.com.

Informants could be eligible for a cash reward of up to $1,000, Cohen said.