A 12-year-old boy stabbed a male classmate in an elementary school classroom Monday afternoon in Okayama, police said.
The classmate, also 12, was taken to a hospital, but his injuries were not life threatening and he was conscious, they said.
The incident occurred at Kibi Elementary School, which has 169 students.
The boy is believed to have stabbed his classmate with a penknife close to his left armpit at around 2:30 p.m.
The two students, both sixth graders, had been quarreling during an afternoon lesson prior to the incident, police said.