Cape Town - Pupils at Sans Souci Girls' High School in Newlands, Cape Town, are staging a protest in support of the teacher who was caught on camera slapping a pupil during a heated confrontation.

A video doing the rounds on social media shows the teacher engaged in an argument with the pupil. The teacher can be heard admonishing the girl for having her cellphone at school in contravention of the school's code of conduct.

In the clip, which is about one-and-a-half minutes long, the rest of the class looks on helplessly as the pupil repeatedly backchats the teacher who appears to grow more and more agitated.

During the incident, which reportedly happened on Tuesday, the girl accuses the teacher of swearing at her and this appears to escalate their confrontation.

When the teacher confiscates the pupil's cellphone the girl pushes past her to take to phone from the teacher's table. At this point, the teacher becomes visibly overwrought and slaps the girl, to the horror of her classmates.