A knife fragment and pieces of a stainless steel brush and sponge were found in commercially prepared lunches at an elementary school in Minamikawachi, Tochigi Prefecture, earlier this month, the town's board of education said Thursday.
The foreign objects were apparently accidentally mixed into the food during the cooking process in a preparation room at Gion Elementary School. No students were hurt, the board said.
The board said it terminated school lunches Wednesday and will cancel the contract with the lunch service, Megumi Sangyo of Utsunomiya.
The board plans to resume lunches once a new provider is chosen.
According to the board, a student found a piece of metal about 1 cm long in her mouth while she was eating Nov. 14. School officials discovered it came from a knife used for shredding vegetables in the preparation room.
On two other instances -- Nov. 18 and Tuesday -- students found pieces of a stainless steel brush and sponge in their food before they ate, the board said.
"We were lax on safety checks," a Megumi Sangyo official said. "We are extremely sorry."