A boy of 10 was forced to lie face down while his mother was subjected to a four-hour rape ordeal in a Johannesburg taxi, reports from South Africa say.
He and his mother were allegedly tricked into boarding the minibus taxi before she was assaulted and ordered to hand over her bank card and PIN number by the three armed occupants.
It is thought to be the latest in a string of attacks by the gang.
The first reports of the "rape taxi" were made a year ago.
According to the Roodeport Record, the initial attacks happened in March 2016, with at least three taking place in one week last June. All took place in, or near, the Johannesburg township of Soweto.
But it is unclear how many attacks there have been in the last 12 months, or if they are all by the same gang.
Lt-Col Lungelo Dlamini told the BBC: "A group of three to four men driving in two separate [Toyota] Quantums, one grey and another white, pick up women pretending to be a taxi, rob them at gunpoint and then proceed to rape them."
Mr Dlamini said it was not known whether the two Quantums were working separately or together.
Praying for her son
So far, two women - including the mother - have talked to local media in South Africa, describing their ordeals.
The second woman told Kaya FM how a man who had found her after she was attacked had helped another two potential victims he found in the same spot.
She also said the gang had been carrying a card machine, according to Africa News Network.
Both women were picked up during the day, the mother at 11:00, and the lone woman at 08:00.
After the mother and son entered the taxi, the boy was made to lie face down on the floor, while the men raped his mother.
The victim told EyeWitness News she had prayed during her ordeal that the gang would not hurt her child.
South Africa has some of the highest rates of reported rape in the world.