The parent company of Stop & Shop and Hannaford grocery stores has issued a statement saying they were recently impacted by a “cybersecurity issue within its U.S. network.”

Ahold Delhaize USA said Friday that immediately upon detecting the issue, they began an investigation with assistance from external cybersecurity experts and notified law enforcement.

“Our teams are taking steps to assess and mitigate the issue,” the company said. “This includes taking some systems offline to help protect them. This issue and subsequent mitigating actions have affected certain Ahold Delhaize USA brands and services including a number of pharmacies and certain e-commerce operations.”

That reportedly impacted some stores’ ability to accept payments by debit or gift cards. Hannaford’s website also wasn’t working all weekend or on Monday. Other stores reported issues with product deliveries as a result of the cybersecurity issue.

All of the company’s stores remain open and are continuing to serve customers, Ahold Delhaize USA said. They also said they will continue to take actions to further protect their systems.

“The security of our customers, associates and partners is a top priority,” the company said. “We apologize for any inconvenience this issue may have caused customers and partners.”

Stop & Shop has over 200 locations in New England, including 117 in Massachusetts, 83 in Connecticut and 25 in Rhode Island. Hannaford has 36 locations in New Hampshire and another 68 in Maine.