Nigeria is MTN’s biggest market, with 58 million users in 2018 and accounts for a third of the South African group’s core profit.
MTN Nigeria said there will be no disruption to its telecom services across the country.
“The safety and security of our customers, staff and partners is our primary concern,” MTN Nigeria said in a statement.
Police have yet to pinpoint what triggered the violence, which began on Sunday when protesters armed with makeshift weapons roamed the streets of Pretoria’s business district, pelting shops with rocks and petrol bombs and running off with goods.