TOKYO A 41-year-old Japanese science teacher forced his students to drink diluted hydrochloric acid as punishment for showing up late to his class, reports said Tuesday.

The junior high school teacher in Nagoya, central Japan, ordered three students to drink the acid in 1996 but none of them got sick, AFP quoted Jiji Press and Kyodo news agency as saying.

The teacher, whose name was withheld, also drank the diluted acid, the reports said, quoting officials from an educational board in Nagoya. The board officials could not be reached for comment.

The Nagoya Educational Board learned about the incident following an anonymous telephone call telling of the drinking punishment.

One board official was quoted by the Kyodo news agency as calling the teacher's action "inappropriate."