Maintaining calm in a classroom may be a tough challenge for many elementary school teachers, but one in Mie Prefecture resorted to the ultimate step to ensure silence — taping a student's mouth to shut him up.

The Mie Prefectural Board of Education on Monday punished the 44-year-old male teacher at Wagu Elementary School in the city of Shima by slashing his salary by 10 percent for the taping incident in June.

The school offered an apology to the boy's parents the following month after they lodged a protest.

"The teacher's act constitutes corporal punishment. We will ensure that teachers won't resort to such a step," a board official said.

Earlier reports said the student, a fourth-grader, wouldn't stop chatting with his friends during class on June 6. This prompted the teacher to cut a 10-cm strip of adhesive tape and place it on his mouth.

When the boy took it off immediately, the teacher then wrapped tape around his head, city officials said.