Fast-food giant KFC has apologized to its German customers after it used the anniversary of the event that instigated the Holocaust to promote its chicken.
Users of the chicken chain’s German app received a push notification on Wednesday that read: “It’s memorial day for Kristallnacht! Treat yourself with more tender cheese on your crispy chicken. Now at KFCheese!”
Around an hour later, KFC sent a second alert to app users, according to German newspapers.
“We are very sorry, we will check our internal processes immediately so that this does not happen again,” the company said via push notification. “Please excuse this error.”
Kristallnacht is the name given to a wave of violent attacks on Jewish communities that took place throughout Germany and Austria over two days in 1938. The name, which translates to “Night of Crystal,” refers to the shattered glass from synagogues, homes, and Jewish-owned businesses that was left in the streets in the wake of the destruction.
Kristallnacht—also known as “Night of the Broken Glass”—marked a turning point for Jewish people living in Nazi Germany, a regime that went on to murder at least 6 million Jews.
KFC’s mishap is reported to have occurred when an automated system—which was designed to detect holidays and other days of significance and write relevant marketing messages—identified the anniversary of Kristallnacht and generated the push notification.
Messages created by the system are supposed to be checked by a human being before being sent to users, according to the BBC, but this one slipped through the cracks.
A spokesperson for KFC was not immediately available for comment when contacted by Fortune.
However, in a statement to Newsweek, the company’s German operation pointed the finger at its bots.
“Automated push notification was accidentally issued to KFC app users in Germany that contained an obviously unplanned, insensitive, and unacceptable message, and for this we sincerely apologize.
“We use a semiautomated content creation process linked to calendars that include national observances,” it said. “In this instance, our internal review process was not properly followed, resulting in a non-approved notification being shared.”
The company said it had suspended app communications while it examined its current processes to ensure similar problems did not arise again.
“We understand and respect the gravity and history of this day, and remain committed to equity, inclusion, and belonging for all,” it told Newsweek.
KFC has faced widespread condemnation over the blunder, with Twitter users taking to the platform to declare the promo “disgusting” and “pure anti-Semitism.”
Daniel Sugarman, director of public affairs for the Board of Deputies of British Jews, described the marketing message as “absolutely hideous,” while Dalia Grinfeld, associate director for European affairs at Jewish NGO Anti-Defamation League, said in a message directed at KFC: “Shame on you.”