A dispute between Mozambique's interbank payments system operator and its IT provider which has led to accusations of "blackmail" has left millions of people unable to use their cards at the point-of-sale or ATMs.
SIMOrede, which is majority owned by Mozambique's central bank, is suffering an outage affecting around 2.2 million cards.
Customers of several banks are unable to use their cards, although the country's largest lender, Millennium BIM, is unaffected because it is not on the system.
According to Bloomberg, SIMOrede chairwoman Gertrudes Tovela told reporters on Sunday that she does not know when the issue will be resolved.
With long lines developing outside of bank branches, Tovela put the blame on a contract dispute with a technology provider. She did not name the firm, saying only that it is Portuguese.
According to All Africa, Tovela said that the IT firm is making contractual demands. The situation is critical "but it would be worse if we were to accept these conditions, because the blackmail would continue".
SIMOrede is refusing to negotiate with the provider and is instead looking for an alternative firm.