Twenty public school teachers were punished for disobeying an order to stand and face the flag during the singing of the national anthem in graduation ceremonies in March, the Tokyo Board of Education said March 31.

The punishments ranged from a 10 percent salary cut for between one and six months to six-month suspensions from work and nonrenewal of contracts for temporary or part-time workers.

The board has been punishing teachers since ordering public school principals in October 2003 to instruct teachers and students to stand and sing Kimigayo at graduation and entrance ceremonies.

About 400 teachers have been punished so far.