The 13-year-old was throwing snowballs in Chimswell Way, Haverhill, Suffolk, on Tuesday afternoon when a passing car was struck by accident, she said.

The motorist got out of his car, struck the teenager across the back of the head before kneeing him in the face and threatening to break his neck.

A police spokesman said it was a "nasty attack on a young child".

On Friday, the boy's mother, who wished to remain anonymous for fear of reprisals, added: "My son and his friends were walking home from school. They were just playing like kids do and throwing snowballs at each other.

It's not normal for someone to react like that - he's going to end up killing someone with his temper Victim's mother

"This car happened to drive past and a snowball hit it. They were not aiming at the car; it was just passing.

"He could have killed my son. It's only because there were houses there that he didn't go further and do something even more serious.

"This man obviously has a very volatile temper to do this to a school child over a snowball.

"It's not normal for someone to react like that. He's going to end up killing someone with his temper."

A police spokesman said: "This was a particularly nasty attack on a young child. Fortunately his injuries were not serious, but there was the potential for them to be much worse."

The driver was described as white, between 25 and 35 years old, about 5ft 11in, with shaved hair and was wearing a white jumper.