Police desperately searching for missing 3-year-old, 2 persons of interest in custody

Authorities in Alabama say they have no information on the whereabouts of a missing 3-year-old girl who was believed to have been abducted while attending a birthday party this weekend.

Two persons of interest are being questioned as the search for Kamille "Cupcake" McKinney intensifies, Birmingham Police Chief Patrick Smith said Monday.

Kamille was playing with other children at an outdoor birthday party in the Avondale neighborhood of Birmingham on Saturday night when she vanished, authorities said.

The Alabama Law Enforcement Agency issued an Amber Alert that night, which said the toddler is considered to be in "extreme danger." Investigators are expanding the Amber Alert to surrounding states.

Investigators believe Kamille was picked up by an unknown man in an older, dark-colored Toyota Sequoia with beige trim. The vehicle was found Sunday after police received several tips from citizens in the community, Smith said.

The chief did not elaborate on the two persons of interest in custody but said other people are believed to be involved.

"We're putting the pieces of the puzzle together, but as you know it takes time to follow the leads," Smith said at a news conference on Monday.

Smith said there was "a little bit of a delay" in reporting her missing to law enforcement as families often think they can search on their own.

"We will not end our command post or our search until we've found some resolution," Smith said. "We're going to stay committed."

"I want her back bad," Kamille's father told Birmingham ABC affiliate WBMA. "I'd do anything to have my baby back."

Alabama Gov. Kay Ivey said in a statement Monday, "It is imperative that we remain vigilant and report any information that may help law enforcement bring her home."

"We are in discussions with Jefferson County District Attorney Danny Carr to finalize plans for my Office to offer a $5,000 reward for any information leading to the arrest and conviction of the perpetrator(s) and the location of Kamille," Ivey said. "We offer our fervent prayers for law enforcement and all involved in the search. We pray for Kamille's family and that God will continue to watch over Kamille until she is safely returned home soon."

Kamille, who is black, was described as being about 3 feet tall and weighing 60 pounds. She has brown eyes and black hair. She last seen wearing a pink T-shirt with a leopard print Mickey Mouse face and leopard print shorts. She did not have shoes on at the time.

Police have asked members of the public to immediately turn over any photos or video from the birthday party that evening.

Anyone with information on her whereabouts is asked to immediately call 911.

ABC News' Rachel Katz and Amanda Maile contributed to this report.