The latest incident happened at about 10am on Wednesday, in Eisleben Road, Nyanga, said police spokesperson Andrè Traut.
Golden Arrow spokesperson Bronwen Dyke-Beyer said passengers and the driver were robbed by four unknown perpetrators who boarded the bus at two different points along the route.
Dyke-Beyer says about 20 similar incidents have been reported since September.
She said they believed it was the work of a criminal syndicate operating in the Philippi area, and confirmed the police were following a number of leads.
“Golden Arrow is still offering a reward of R50 000 for information which leads to the arrest and conviction of these brazen criminals,” Dyke-Beyer said.
Community Safety MEC Alan Winde condemned the attacks on commuters.
“It is clearly becoming a trend, given the recent spate of incidents on Golden Arrow buses,” Winde said.
“Criminals have seen a gap and are seizing an opportunity. We need to become innovative to curb these attacks and remain one step ahead of criminals who are seeking to exploit hard-working, law-abiding citizens, who rely on these services to safely get to their destination,” he said.