A Tuesday morning tip led police to search the Leakin Park area for Phylicia Barnes, who went missing December 28.

- The FBI has joined the search for a 16-year-old girl who went missing while visiting siblings in Baltimore, Maryland, police said Tuesday.

Phylicia Barnes, from North Carolina, was spending Christmas with relatives. She was last seen at the Reisterstown Square Apartments in northwest Baltimore.

"Every hour that passes we are more and more concerned," said police spokesman Anthony Guglielmi.

Police have no evidence the girl met foul play and there are no suspects.

Still, dozens of detectives and officers are working around the clock to find her, Guglielmi said. Barnes has been missing since December 28, when she was at her half-sister's apartment.

The teen's mother, Janice Sallis, told HLN's Jane Velez-Mitchell and CNN affiliate WSOC that the girl may have been permitted to drink an alcoholic beverage.

"I was infuriated," Sallis told WSOC.

Sallis said she also learned Phylicia was allowed to smoke marijuana.

"I don't think she left anywhere on her own," said Sallis, adding that it was her understanding that up to 20 men had been in and out of the apartment.

Police got a tip Tuesday morning and searched Leakin Park, Guglielmi said. Nothing was found, and it turned out the tip was only a suggestion for an area to search, the spokesman told HLN.

Phylicia Barnes attends Union Academy in Monroe, southeast of Charlotte, WSOC said.

Investigators were also looking at Barnes' Facebook page for any clues.

Barnes was scheduled to return to North Carolina on Monday but didn't show up for her flight, CNN affiliate WBAL said.