Wendy’s (WEN) is feeling the pinch of meat shortages and has taken burgers off its menu in some locations.

The fast-food chain, which uses fresh beef patties, has found it difficult to maintain its meat supply, causing an interruption in its burger service in the past week, sources told Restaurant Business. A number of meat processing plants have closed because their workers have tested positive for COVID-19.

Wendy’s told the news outlet that it is working to “minimize the impact to our customers” at it more than 5,800 restaurants located across the U.S.

"It is widely known that beef suppliers across North America are currently facing production challenges," Wendy's told USA Today in a statement. "We continue to supply hamburgers to all of our restaurants, with deliveries two or three times a week, which is consistent with normal delivery schedules.

“However, some of our menu items may be temporarily limited at some restaurants in this current environment. We’re working diligently to minimize the impact to our customers and restaurants, and continue to work with our supplier partners to monitor this closely,” the company added.

Twitter users were quick to point out the fast-food chain’s previous ad slogan, “Where’s the beef?” in relation to the burgers going missing from its menus. One Twitter user said, “ @Wendys I tried to get a baconator today, but they said they were out of burgers because there's a beef shortage. So I gotta ask... Where's the beef?”

Several users took to Twitter to show signs hanging at Wendy’s drive-thrus announcing the beef shortages. In one Tweet, a user said, “ @Wendys really y'all? A burger place out of burgers? Every one else still has them.”

Another user said, “ Tried to order some burgers from our local Wendy's and they were sold out of burgers. Sold. Out. So that leaves me with one question: Hey @Wendys, where's the beef?”

Shares of Wendy’s stock were down 3.35% as of 11:23 a.m. EDT on Tuesday.

On Wednesday, the Wendy's Twitter account started to give serious and genuine movie reviews to questions posed by users. Here, The Wendy's sign is seen outside their restaurant in Bowie, Maryland, May. 9, 2017. Jim Watson/AFP/Getty Images