The 24-second video shows the victim being confronted by a bigger boy who keeps asking him in isiZulu "what were you saying" while he smacks him over the head.
With his backpack still strapped to his back, the young boy does not reply. Instead, he covers his head in an attempt to protect himself from the series of blows.
All of a sudden, another boy joins in the assault. He smacks and punches the victim before being joined by a third attacker, who too slaps the victim.
One boy comes and pulls the second attacker away.
All the while, the person believed to be taking the video can be heard chuckling in the background. It is unclear how the altercation ended.
The mother said when she asked her son what had happened, he simply said some boys had beaten him up.
According to the boy's mother, the principal claimed to have received the video on February 4.
"It was sent to him by the uncle of the big boy who is seen hitting my son. The uncle was shocked by the incident after receiving the video from another family member," the mother said.
WATCH | Cellphone footage emerges of shocking schoolboy bullying
Despite the noise of schoolboys shouting, laughing and talking, the slaps that collided with the child's head can clearly be heard.
They came thick and fast. More than a dozen slaps - thrown by three different students - were landed in just 20 seconds, as the victim tried to defend himself by wrapping his arms around his head.
A relative of a grade 8 victim has shared the video of the attack to highlight the terror and trauma of bullying in schools. It was filmed at the Duvha Combined School in Witbank. The video has since gone viral.
The boy's mother said the incident happened on January 30.
"The big boy seen in the video is a grade 9 learner and he is a prefect at the school. According to my son, some pupils had been stoning the security guard's houses near the school and [the prefect] reprimanded those who were doing this.
"My son joined in and told those throwing stones to stop and, apparently, this boy [the prefect] was angered, feeling my son is taking his job," said the distraught woman.
On the day of the attack, she said she was off from work and her son had returned home acting strangely. She offered him a pie but he said he was not feeling well and would just head to bed. Without looking at his mother, he accepted pain killers and went to his room.
For several days after that, she had to force her son to hurry and get ready for school, noticing that he was stalling every morning.
She said she only learnt of the video on February 6, a full week after the incident happened. She was only made aware following a phone call from the school principal.
"The principal called me to say that he had been to the police station to write a report on the incident. He explained to me that there was a video of bullies at the school and my son had been part of the incident."
Taking to her Facebook page, the aunt - whom we have chosen not to name in order to protect the bullying victim's identity - said there was "no punishment whatsoever" for the boys responsible for the assault.
"And now my nephew is traumatised," she said.
She said the boy no longer wanted to go school following death threats.
"Ever since this assault, my nephew would cry when his mom drops him off at school or would lie and say he's got a stomach bug just to avoid this issue of going to school. Can you imagine the trauma?" the woman said.
"How many kids are being abused and told to keep quiet?" she asked.
The 24-second video shows the victim being confronted by a bigger boy who keeps asking him in isiZulu "what were you saying" while he smacks him over the head.
With his backpack still strapped to his back, the young boy does not reply. Instead, he covers his head in an attempt to protect himself from the series of blows.
All of a sudden, another boy joins in the assault. He smacks and punches the victim before being joined by a third attacker, who too slaps the victim.
One boy comes and pulls the second attacker away.
All the while, the person believed to be taking the video can be heard chuckling in the background. It is unclear how the altercation ended.
The mother said when she asked her son what had happened, he simply said some boys had beaten him up.
According to the boy's mother, the principal claimed to have received the video on February 4.
"It was sent to him by the uncle of the big boy who is seen hitting my son. The uncle was shocked by the incident after receiving the video from another family member," the mother said.
The provincial education department said it was aware of the incident.
Spokesperson Jasper Zwane said they had since directed the school to take action.
"The department directed the school to institute disciplinary proceedings against the learners who are behind this, in line with the school code of conduct," Zwane said.
"Officials from the department will visit the school to render counselling to the victim and to those affected by the incident. The department condemns this incident in the strongest terms possible and will monitor the developments very closely," he added.
The victim's mother said the boys behind the assault had since been put on suspension but she was hoping that the trauma of what had happened to her son would not affect him forever.
"He is a quiet and shy boy and it just disturbs me to know he went through this and continued to go to school each day where people were pointing at him, saying 'he was the one who was beaten'. I am speaking out now, not just for my son but for other children who are victims of bullying," the woman said.
She said she had opened a case of assault with the police.