TRACY, Calif. -- The mother of a missing Tracy 8-year-old girl issued an emotional plea for her return Tuesday while authorities questioned two “persons of interest” including a man seen kissing the girl two years ago.

Supported by a friend, Sandra Cantu’s mother Maria Chavez was teary eyed as she met with reporters briefly on Tuesday morning.

“Please whoever has her, just let her go,” Chavez pleaded. “She needs to come home to her mom who loves her very much and misses her.”

Meanwhile overnight, investigators searched six separate locations, they interviewed two “persons of interest” including a man seen kissing Cantu on the mouth two years ago and the FBI towed away two vehicles from the mobile home park, authorities said.

Late Monday, the Tracy police did confirm that a search of mobile homes at the park where Cantu disappeared from last Friday has turned up evidence, but said the child has still not been located.

Police also searched a home in the Central Valley town of Oakdale. Investigators say they obtained search warrants based on info obtained thru interviews with residents. So far, no one's been taken into custody.

Officers continue to search the trunk of each vehicle leaving the mobile home park. Earlier Monday evening, three unmarked FBI vans and a tow truck arrived at the park. A neighbor tells KTVU he saw federal agents removing evidence from another neighbor's house and that the tow truck was preparing to remove that neighbor's vehicle.

The girl was last seen around 4 p.m. Friday afternoon outside her home at the Orchard Estates Mobile Home Park near Interstate 205. Police say a surveillance camera recently installed by her family captured an image of the second grader as she was seen leaving her mobile home.

Family and friends of the missing girl are holding onto the belief that she will be found safe and sound. For the third night in a row, they held a candlelight vigil to keep hope alive.

Dozens of people gathered for the vigil just inside the front gates of the mobile home park where Sandra Cantu lives. The eight-year-old had just celebrated her birthday two weeks ago.

Monday afternoon, her mother Maria Chavez made a tearful plea for her daughter's safe return.

"Whoever took her, please bring her back home," said Chavez. "I miss her so much. I love her. I want her to know I love her. We're looking for her. We're doing the best we can to find her."

Monday evening, police met with hundreds of concerned parents at Jacobson Elementary School where Cantu is a student.

"We are depending on information from the community," said Tracy Police Sgt Tony Sheneman.

One parent, whose daughter is friends with Sandra and lives near the missing girl, told police she saw a suspicious black Jeep Cherokee in the neighborhood around the time Sandra disappeared.

Local resident Kim Bravo was visibly shaken.

"It just worries me. We're kind of new out here and it hurts as a mother. It really does," explained Bravo

Bravo's daughter Aliah Peralta describes Sandra as being friendly and kind to everyone.

"She'd talk to anyone. She just came up to me when I met her and asked me what my name was," said Peralta.

Police and the FBI say they've received more than 150 tips, including some credible leads.

Investigators have interviewed registered sex offenders in the area and plan to re-interview a man living in the park who kissed Sandra on the mouth at the community pool two years ago

Police re-searched the 100 mobile homes in the neighborhood, but still say they have no person of interest or evidence that Sandra has been harmed.

"[I] just hope they find her. It's been a long time It was really cold last night, and if someone has her, just let her go," said neighbor Anthony Camarena.

Police are reviewing hours of surveillance video from nearby businesses and have searched foreclosed homes and businesses in the area.

On Monday, the reward for anyone who provides information that help police to find Cantu went up to $7,000.