The logo of the market chain 7-Eleven (symbol image)
Photo: Toru Hanai / REUTERS
The US chain 7-Eleven has closed its stores in Denmark due to a suspected cyber attack on the checkout system.
The company announced on Facebook on Monday that it assumed it had "been the victim of a hacker attack".
7-Eleven operates 175 convenience stores in the country.
The alleged attack happened spontaneously, suddenly all cash registers failed, said the chain's Denmark manager, Jesper Ostergaard, on Danish television.
Such an incident has never happened before.
"We remain closed until we know the extent," said 7-Eleven with reference to the hacking attack.
7-Eleven is based in Irving, Texas.
The chain operates over 77,000 stores worldwide, either directly or through license agreements.