Thousands of cottage cheese cases have been voluntarily recalled because they may be contaminated with metal and plastic pieces.

According to the Kraft Heinz Food Company, the recall involves three types of its "Breakstone" cottage cheese -- the 2-percent low-fat large curd cottage cheese, as well as its small and large curd 4-percent cottage cheese.

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The company says it has received six complaints from consumers, but no reports of injuries. They say the pieces can cause injury to the mouth, throat, teeth, and stomach.

Consumers are urged not to eat the products, and return them for a refund.