A group of teenagers accused of raping a girl believed to be mentally impaired appeared in the Roodepoort Magistrate's Court on Wednesday.

The trial was postponed to November 27 because three of them were writing examinations, National Prosecutions Authority spokeswoman Phindi Louw said on Wednesday.

Five teenagers, aged between 17 and 18, have been charged with rape, sexual assault, and using a minor to create child pornography.

They were arrested after a cellphone video, which they allegedly recorded, of a 17-year-old girl being gang-raped appeared on the internet.

The video went "viral" on social networking sites.

The girl had gone missing and was found at a 37-year-old-man's house in Braamfischerville, Soweto.

He was arrested but charges against him were later withdrawn.