The Department of Basic Education (DBE) has urged high schools not to discriminate against students who are well advanced in age.
This comes amid incidents involving 21-year-old school pupils across the country.
In the Free State, a 21-year-old Grade 12 pupil recently stabbed Matefo Mphosela, a 35-year-old physics teacher, to death at her house late in the evening.
The police are probing circumstances around the incident.
In Gauteng, a 21-year-old Grade 11 learner was arrested after fatally stabbing a schoolmate at Qalabotjha Secondary School in Vlakfontein.
The incident is suspected to have been related to gangsterism.
Meanwhile, in KwaZulu-Natal, another 21-year-old is in court for allegedly gang-raping a schoolgirl on the school premises.
The news was confirmed to IOL by KZN SAPS spokesperson Nqobile Gwala.
The alleged incident occurred in Pietermaritzburg last week, and the police confirmed, on Thursday, that the suspects were charged.
“We have arrested three suspects between the ages of 16 and 21.
“The two, who are juveniles, were released into the custody of their parents.
“So the other one, who is still in custody, is a 21 year old and will appear in court for a formal bail application," said Gwala.
DBE spokesperson Elijah Mhlanga, told IOL that the school system regulates the age of youngsters who should be in school per grade.
“Some learners become over age because of repetition and schools are not allowed to chase them away,” he said.
To help remedy the situation of over-age pupils, Mhlanga said the department has support programmes in place for learners who are struggling academically.
He said social misconduct also reflected on the experiences of the youth within their communities.
He said parents and guardians should play their part to ensure that such behaviour was not seen at schools.