Ahold Delhaize USA said a cybersecurity issue in its network disrupted digital services for several grocery chains, including Food Lion, Stop & Shop and Hannaford.

The company said it took some systems offline as a precaution while investigating the incident and working to restore affected services. In a statement updated Tuesday, it said it had begun a controlled relaunch of some systems as its assessment and mitigation work continued.

Food Lion’s website reported that its website and app were unavailable and said customers could place delivery orders through Instacart, DoorDash and Uber Eats. The chain said unfulfilled orders placed through its own website or app would be refunded.

The source reported that the stores remained open. It did not provide details about the nature or scope of the cybersecurity issue, whether customer information was affected, or when all services would be restored. Ahold Delhaize USA had been contacted for more information, according to the source.