Sassa's Mbizeni Mdlalose says the gang fled in a vehicle.
He says there is no need for social grant beneficiaries to worry, promising that payments will be made on time.
"We are using an online system, which means that we do have a back-up. It is not a manual system, people will be paid as normal," said Mdlalose.
He said contingency plans have been put in place to ensure the office operates as per normal.
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