"According to witnesses, two vehicles smashed into the SBV van. Three suspects in police uniform allegedly pointed firearms at the SBV guards in the vehicle, and then made off with an undisclosed amount of cash as well as three firearms belonging to the security guards," said police spokeswoman Brigadier Mathapelo Peters.
"Police believe there could have been more than three suspects and are therefore appealing to anyone who may have information that could lead to the apprehension of the suspects, to come forward and contact the police."
The vehicle was transporting cash to the Pretoria CBD.
No shots were fired during the incident.