Pictures from the scene showed a red car pinned under the side of the bus and a white work truck also wedged against the larger vehicle.
Officials said Bus 220 was on a McGee's Crossroads Elementary School route when the accident happened. Forty eight students were on board at the time.
Fifteen students were taken to area hospitals including Johnston Medical Center in Smithfield and the Johnston Medical Center in Clayton. The injuries appeared to be minor. The bus driver was also taken to the hospital to be checked out.
At least one person in the car was seriously hurt and two others in the truck were also hospitalized.
The North Carolina Highway Patrol is investigating.