A cash van which had just collected money near a Post Office was robbed and then bombed in Lotus Gardens, Pretoria West, on Tuesday, police said. 

Police spokesperson Lieutenant Colonel Katlego Mogale said a white Ford Ranger and a black Audi approached the van as it was on its way and forced it to stop. 

"They opened the cash vehicle, took out the bags of cash, and loaded them into the Ford Ranger," said Mogale. 

"They then bombed the cash vehicle and fled the scene. The suspects were armed with pistols and rifles." 

The two security officers in the van were uninjured.

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Police are yet to determine the amount of cash taken.

A case of armed robbery is being investigated. 

In pictures from the scene, one side of the van appears to have been prised open like a tin can and the metal inside was twisted. 

Bags were strewn across the road and on the verge as police cordoned off the suburban street.

There were unconfirmed claims that some of the people drawn to the scene "looted" after the robbery.