A foreign teacher was found to have forced students to eat detergent as punishment for using Korean language in his class, which is stirring public anger over the lack of monitoring in the classroom.

According to the Seoul Metropolitan Office of Education, a 32-year-old teacher from South Africa forced five elementary school students to taste either dishwashing detergent or bad-tasting medicine for talking in their mother tongue.

Facing mounting complaints and criticism from parents, the school immediately apologized for the incident and dismissed the teacher, SMOE officials said Friday.

The teacher reportedly claimed that it was only a negligible amount and that he did not compel the children to taste it.

“As private schools employ foreign teachers on their authority, it is their responsibility to monitor and supervise the foreign teachers,” the city education office said.

Further investigation into the incident is underway, it added.

By Lee Hyun-jeong (rene@heraldcorp.com)