An eight-year-old boy is being hailed as a hero after dragging his sister from a moving car to save her from a potential kidnapping.

The pair, identified by police as Chance and Skylar, were in the back seat of the car outside a hospital in Ohio as their grandmother took a friend to the emergency room.

Around 10 seconds after 69-year-old Nita Coburn exited the car outside the Atrium Medical Center, a man jumped into the front seat and started to drive off, according to Middletown Division of Police.

In a Facebook post, the police wrote: “The little boy opened the door to escape and the little girl started to jump out also but the man grabbed the hoodie of the little girl not allowing her to leave.

“As she tried to get away her little brother grabbed hold of her and pulled her away from the kidnapper and they both tumbled out of the vehicle as it was moving."

Unaware that her grandchildren had managed to escape on the passenger side of the car, Ms. Coburn then pursued the vehicle, running and clinging on to the driver side until it started moving so fast she had to let go.

Chief Rodney Muterspaw praised Chance's actions, calling him a “hero".

He said: “This little guy is a hero. No question. He pulled his sister out of the car with no concern for his own safety. That is incredible at his age."

Police caught up with the vehicle nearby, and they said Dalvir Singh, a 24-year-old from India, had been charged with two counts of kidnapping, felonious assault and grand theft.