The local units of South Africa’s MTN Group and supermarket chain Shoprite, closed all stores and service centres in Nigeria after their premises were attacked following days of riots in their home country chiefly targeting foreign-owned, including Nigerian, businesses.

The violence in South Africa has strained relations between Africa’s two biggest economies, with Nigeria saying on Thursday it would recall its top diplomat to Pretoria.

MTN Nigeria said its stores remained closed on Friday but skeletal office operations were resuming, its spokesman said, adding that staff were asked to stay at home for safety reasons.

Shoprite stores remained shut except for one in an upmarket area of the capital Abuja, a manager there said.

Shares in MTN, Nigeria’s second-biggest listed firm, rose 5.03% to 139.80 naira each, a level last seen in June. Johannesburg-listed Shoprite shares were up 1.8%.

Prior to the shutdown, the telecoms firm last week launched a mobile money transfer service, targeting Nigerians without bank accounts, and said it planned to become a payment services bank once it obtains approval from the central bank.