Counselling has been arranged for pupils at Noordwyk Secondary School in Midrand, Gauteng, after two Grade 11 pupils took their own lives, the provincial education department said on Friday.
Dimakatso Shai, 17, allegedly took her own life on Monday, while 18-year-old Seandaryl Masuku died on Thursday.
Education MEC Panyaza Lesufi said police were investigating the circumstances surrounding the deaths.
"It is unfortunate and regrettable that learners took their own lives in this manner. We take this time to send our heartfelt condolences to the family, friends and the school community, during this time of grief.
"No words are enough to express our sorrow at a loss of a child. We hope that the families will find comfort in the knowledge that we too share their loss."
A memorial service was held for Shai on Thursday. She will be buried on Saturday.
Memorial and funeral services arrangements for Masuku will be announced in due course.