Forest High School in Turffontein, Johannesburg, is "a prison", where gangs thrive and younger boys are forced to perform sexual acts for older pupils, according to a report.
On Monday, Daniel Bakwela, 16, was stabbed to death outside the school, allegedly by a fellow pupil.
Two other pupils were also attacked and were hospitalised.
The Star reported on Tuesday that one of the surviving victims was being bullied for four months prior to the attack.
News24 reported on Monday that a 19-year-old suspect had been arrested following the incident.
Police spokesperson Captain Mavela Masondo said the suspect had fled the scene, but that police were able to trace him to Dobsonville in Soweto, where he was arrested.
"The motive…is unknown at this stage and police investigation is continuing. The suspect will appear in the Johannesburg Magistrate's Court on Wednesday, facing charges of murder and attempted murder," he said.
According to The Star, conditions at the school are dire and akin to a prison.
'They tell you to massage their penises'
"This school should be called 'Forest High Correctional Service'. When you get into the toilet, the older guys tell you that this is not a place for small boys and you are forced to pay money," a pupil told the newspaper.
"They also tell you to massage their penises and make them ejaculate. Almost 99% of the school is either on weed or some kind of a drug," another pupil reportedly said.
According to another pupil, two rival gangs – the South Top Kids and the Italian Destruction Vele – had members inside and outside the school.
Gauteng Education MEC Panyaza Lesufi, who arrived at the school shortly after the incident, said all four of the pupils involved in the stabbing incident had attended the same school, News24 reported.
According to Lesufi, the stabbings occurred after a scuffle had broken out between the victims and the suspect last week.
Lesufi said the suspect had been writing his examinations on Monday. The three victims, who had no examinations scheduled for the day, were allegedly waiting for him outside the school.
Lesufi has suspended classes with immediate effect.
"We have asked the principal to communicate with the parents. We have quarantined the school for the next 48 hours to provide all relevant support that is needed to those who witnessed the stabbings and to friends of the deceased," he said.
News24 quoted a pupil who said gang fights were the norm at the school, claiming that Bakelwa and his friends were gang members who fought with the suspect's gang on a regular basis.
"They were carrying sjamboks and bricks and the suspect, who was being attacked, took out his knife and stabbed three boys from the STK gang," said a Grade 11 pupil, according to Sowetan.
'Can't wait to leave this place'
"I can't wait to complete my matric examinations and leave this place. I am tired of seeing my fellow pupils fighting each other at school," a pupil told The Star.
According to The Star, the school's Grade 12 pass rate for 2018 was 59%, while the overall performance of the other grades had deteriorated over the past three years.
One of the victims of Monday's attack claimed to have been bullied into silence at the school.
The boy, who cannot be named because of his age, was reportedly discharged from hospital on Tuesday and had stitches administered to his lower back.
"I was bullied for four months. It always used to happen and I tried fighting back. The only thing I want is for the older pupils at the school to be removed. They are bad news," the boy reportedly said.
Gauteng education department spokesperson Steve Mabona could not be reached for comment by News24. Mabona, however, told The Star that the allegations of sexual misconduct would be investigated.
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