An Amber Alert was issued Sunday morning for a 4-year-old girl whose stepfather told police she was kidnapped by three men who released him and his 2-year-old son after abducting all three of them, Houston police said.

Authorities originally said the girl was 5.

Maleah Davis' stepfather, Derion Vence, told police he was driving to George Bush Intercontinental Airport on Friday night to pick up Maleah's mother, who was on a return flight from Massachusetts when he heard a popping noise and thought he had a flat tire.

He said that when he pulled over, he was approached by two men who assaulted him and knocked him unconscious, police said. Vence said he woke up briefly while in a vehicle with three men and the two children, according to police.

Maleah Davis in an undated photo. Houston Police Department

Vence told police he was in and out of consciousness until about 6 p.m. Saturday when he and his son were dropped off in Sugar Land in southwestern Houston.

Maleah and the blue Chevrolet crew cab pickup truck he said they were in was gone, according to police. The vehicle that Vence was driving on the way to the airport — a silver Nissan Altima with Texas paper tag 330-92G9 that belongs to Maleah’s mother — is also missing, Sgt. Mark Holbrook of the Houston Police Department’s Homicide Division said.

"We would love for the public to help us so we could fill in the blanks in this story," Holbrook told reporters at an afternoon news conference. "I realize that there’s a lot of blanks in that story."

Vence told officers he walked to a hospital in Sugar Land, where he was treated for minor injuries and reported Maleah missing. The 2-year-old boy was not harmed.

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Maleah is described as 3-feet tall and weighing 30 pounds. She was believed to be with three men in the blue Chevrolet pickup, police said. She was last seen wearing a pink bow in her hair, a light blue zip-up jacket, blue jeans and gray, white and pink sneakers.