H&M at the Gateway mall in Durban was on Tuesday forced to close, following a planned protest by the Economic Freedom Fighters (EFF).
According to reports by Timeslive, the store issued an announcement in-store requesting customers to vacate for safety reasons.
A notice at the entrance of the store read: "This store is temporarily closed. Apologies for any inconvenience caused."
Police posted outside the store said about 14 protesters in EFF regalia were prevented from entering the mall by security.
"They were shown to the nearest taxi rank. We are monitoring the situation," said the police officer.
On Twitter, H&M said it was aware of incidents at its South African stores, and apologised for the advert that caused widespread outrage across the globe.
Stores neighbouring H&M at Gateway also shut their doors and said they were taking no chances.
The EFF has been using the racism furore over H&M's "Coolest Monkey in the Jungle" UK advert as an excuse to vandalise the brand's stores for several days.