AMSTERDAM, Oct 16 : Websites and online delivery services at grocery chains belonging to Dutch supermarket operator Ahold remained offline for a fifth day on Friday following what the company has described as a "cybersecurity incident" that prompted it to shut down some of its own IT systems.

An Ahold spokesperson said the parent company cannot comment about the situation at its individual chains. Its US brands, which include Stop & Shop, Giant Food, Hannaford and Food Lion, are collectively one of the largest food retailers in the United States. Physical stores remain open.

Ahold's Albert Heijn chain, the Netherlands' largest, has been gradually recovering from the shutdown that began October 11, disrupting its distribution centres and leading to empty produce shelves. Albert Heijn does not expect online delivery to resume before Sunday.

The Netherlands' Justice Minister David van Weel called on the company on Friday to file a criminal complaint over the incident, which Ahold has avoided describing as a hack, saying in a statement that no "customer, associate and partner data was taken".

"I understand that in the heat of the moment, a company like this is concerned with preventing damage to its systems and is not immediately looking outward," the minister told Dutch press agency ANP. "I think that we're in calmer waters now and the time has come to take this step." The Ahold spokesperson said the company could not respond to the politician's remarks and pointed to its most recent statement on October 14, in which it said the company was working with relevant internal teams and external cybersecurity experts and engaging with the appropriate authorities and other stakeholders as necessary.

That statement said that because Ahold's investigation is ongoing, it could not share details about what happened in order not to undermine its own security or interfere with its response.