Some People Are Not Lovin' McDonald's Mozzarella Sticks

— -- "So where's the cheese in my mozzarella sticks, McDonald's?"

That's the question one unhappy McDonald's customer recently asked on Twitter, and dozens of other social media users have chimed in, claiming they received cheese-less mozzarella sticks from the burger chain.

Along with comments like, "Hahaha, McDonald's mozzarella sticks are a joke" and "McDonald's y'all slacking," disappointed customers have shared photos of breaded sticks with a hollow center for two weeks.

McDonald's media relations department has responded to the uproar and apologized, saying the cheese melted out of its breaded casing during the baking process.

"We are aware of a low volume of guest concerns about our Mozzarella Cheese Sticks," communications supervisor Jeanette DeBartolo told ABC News today.

"In these instances, we believe the cheese melted out during the baking process in our kitchens and shouldn't have been served," DeBartolo said. "We apologize to any customers who may have been affected. We are working to fix this in our restaurants."

It is not clear if all McDonald's locations in the U.S. have been impacted.