PHILADELPHIA (CBS) — The grandmother of missing 5-year-old Dulce Maria Alavez is pleading for her safe return as authorities continue to search for the young girl. They say time is of the essence to bring her home.

Dulce vanished from Bridgeton City Park between 4 p.m. and 5 p.m. on Monday and police fear she was abducted.

Dulce’s grandmother offered a plea for help Thursday through tears.

“Do not be afraid of the police. We have not been able to eat nor sleep. You can’t imagine what we are going through. We are very sad,” she said through a translator.

UPDATE: grandmother of missing girl #DulceMariaAlavez pleads for help finding her granddaughter (first in Spanish then English) pic.twitter.com/9RWOYlHWcv — Cleve Bryan CBS3 (@CleveBryan) September 19, 2019

Police conducted another K-9 search Thursday in the area of the playground where Dulce disappeared. Bridgeton police have tried a few times to use K-9s that are specially trained to search in areas where lots of people have passed through.

Investigators are also reviewing surveillance video in hopes of identifying the license plate number of the vehicle they believe lured Dulce away from a playground.

Dulce was last seen playing on the swings with her younger brother at the park. Police say her mother, 19-year-old Noema Alavez Perez, was sitting in a parking lot nearby and didn’t see what happened to her daughter.

Police Believe Missing 5-Year-Old Dulce Maria Alavez Lured Away From Bridgeton Playground By Man

After two days searching every possible area of the 1,000-acre park, police determined the girl had been abducted and issued an Amber Alert late Tuesday night.

The FBI and New Jersey State Police are now assisting in the investigation. Authorities are asking for the public’s help, including a $20,000 reward.

“Anyone who was at the park on Monday afternoon could have information of great assistance to this investigation. Please, we’re appealing to you to call us to help us find Dulce,” Cumberland County Prosecutor Jennifer Webb-McRae said.

Here is the latest @FBI poster for #DulceMariaAlavez there is now a $20,000 reward for info on the missing 5yo girl. Police emphasize those who give tips won’t be asked about their immigration status.

Please RT! pic.twitter.com/MtjqjWVUen — Cleve Bryan CBS3 (@CleveBryan) September 19, 2019

Authorities say anyone willing to give them information does not need to worry about questions about their immigration status.

“Time is of the essence, we need to find young Dulce,” Webb-McRae said.

Dulce was last seen wearing a yellow shirt with an elephant, black and white pants, and white shoes.

Authorities believe a man in a minivan took the little girl. They don’t know if he’s familiar to her or a complete stranger.

‘I Just Want To Find Her’: Bridgeton Police Searching For Missing 5-Year-Old Dulce Maria Alavez Last Seen In Park

The suspect is described as a light-skinned, possibly Hispanic, man, standing 5-foot-6 to 5-foot-8 with a thin build. He has no facial hair but he does have acne.

Police say he was last seen wearing orange sneakers, red pants and a black shirt. He was driving a red van with a sliding door and tinted windows.

Police say Dulce’s mother is cooperating with police and the girl’s father is not in the United States. Dulce’s family is desperate to have her back home.

“We as a family, we feel really sad and really bad for not finding my niece. We don’t know who took her, who’s with her, how she is doing and everything. The only thing we’re trying to do is find her,” Dulce’s aunt, Nayiber Alavez Perez, said.

As time passes, a nervous community is growing restless and some have placed flyers on their businesses. Others have signed a petition to add security cameras to the park where Dulce disappeared as they are fearful the suspected kidnapper could be a child predator.

“I’ve lost a child myself and I know how it feels,” Amanda Rush, of Bridgeton said. “I have a 9-year-old and she’s my world and I don’t want anything to happen to her.”

The FBI is asking the public not to clog social media with rumors and speculations, but experts on missing children say credible tips, no matter how small, are crucial.

“Someone out there has a piece of information that could unlock this entire mystery and… they could think it’s not significant, they don’t want to bother the police, but please pick up the phone even if you think it’s insignificant,” said Robert Lowery, vice president of the National Center for Missing and Exploited Children.

Investigators are asking people to call police if they were in the park Monday afternoon.

If you have any information, please call police at 856-451-0033 or text anonymously to TIP411.

CBS3’s Cleve Bryan and Alexandria Hoff contributed to this report.