The trial of 24 people accused of setting alight the houses of two councillors in Chiawelo, Soweto, was postponed by the Protea Magistrate's Court on Friday.
Police said 23 of the people, who were denied bail, would remain in custody and appear again on October 3.
One of the accused, a minor, was released into the custody of his parents, said Captain Mpande Khoza.
At their first appearance in July, magistrate Robert Button described the group as a threat to national security. He feared that victims and witnesses would be intimidated.
The homes of a councillor and a former councillor were set alight during protests by 300 Soweto residents on July 5. The residents claimed their electricity bills and rates were higher than those in other areas. - Sapa