Several Loblaws grocery stores in Toronto were closed Thursday morning after customers were unable to buy items at cash registers because of a computer glitch.

“Due to a technical issue this morning, some Loblaw grocery stores experienced problems completing sales for our customers,” the store’s public relations team said in an email to media. “The issue has been fixed, all of our stores are up and running, but checkout times may be slower than normal. We apologize to our customers for any inconvenience.”

Some self-checkout counters were still experiencing difficulty even as the rest of the store cash registers went back online.

Shortly after 9 a.m., customers began complaining about the issue on social media. Loblaws responded to concerned shoppers from all across Canada on Twitter, saying they were working to correct “technical difficulties.”

According to the store manager at the Loblaws Queen’s Quay location, the outage was caused by a company-wide network issue impacting cash registers,.

He said when they could not ring any customers out at the cash register, the store was shut down. By 10 a.m. it was reopened, although the self-checkout scanners still were not working.

The Loblaws store at Maple Leaf Gardens was also shut down, but has since reopened. There were reports indicating some Shoppers Drug Mart stores were briefly affected as well.