(CNN) -- A mother, stepfather and 7-year-old boy are missing in Mississippi.
They were last seen Friday traveling in a car. The vehicle was later found in the western part of Copiah County, Mississippi. It was flipped, according to the sheriff there.
"We have not been able to rule out foul play," said Copiah County Sheriff Harold Jones.
An investigation is ongoing. The FBI in Jackson is assisting.
All three people missing are African-American. The boy, Jaidon Hill, is 3 feet tall and weighs 44 pounds.
The mother, Atira Hill, is 5 feet tall and weighs 148 pounds. The boy's stepfather, Laterry Smith, is 5 foot 8 and weighs 180 pounds.
According to Hill's mother, Judith Hughes, Hill called early Saturday to say she and Jaidon were on their way to meet Smith's relatives to "take care of some business."
Hughes said she asked her daughter if everything was OK. She said it was.
The phone signal was weak, and eventually the call dropped. Hughes tried calling back, but the call went straight to voice mail.
Hughes said Jaidon lives with her and that he was meant to spend the weekend with his mother.
After the family's car was found flipped, Hughes said she went to the home where Hill and Smith are believed to live. It was empty, she said.
According to her mother, Hill works as a nurse assistant at the University of Mississippi Medical Center.