Wagner, a frozen food manufacturer based in the western state of Saarland, told customers not to eat their “Big Pizza” or “Backfrische” products after bits of metal were found in the bases.
Parts of a machine used to carry flour are thought to have broken off and made their way into the dough mix.
One customer ended up with a two-centimetre piece of metal in his mouth which, he told the company, broke one of his teeth. A woman also told Wagner that she had spotted a shard in her pizza just as she was going to eat it.
Saarland's consumer watchdog voiced concern, with spokeswoman Barbara Schroeter saying that “Bits of metal can damage the stomach and intestines, as well as the oesophagus.”
She added that the company, owned by international food giant Nestlé, would have to explain quickly, and precisely, how metal ended up in its products.
A Wagner spokeswoman said that there was no way of knowing at this point how much money the recall would cost. “We are currently occupied with protecting our customers,” she said.
A company statement advised people in possession of a recalled pizza they could get a refund by either returning to where it was bought or sending the box to the firm in the post.