Chinese state media said Hong Kong schools have become "lawless" as controversy builds over a history question in a school exam, rekindling tensions over academic freedoms in the semiautonomous city.
Beijing and some Hong Kong officials have frequently flagged the education system as a potential breeding ground for the large-scale, often-violent pro-democracy protests which roiled the city in the second half of last year.
The latest row was sparked over a question on a Diploma of Secondary Education test, which asked students to argue whether Japan had done "more good than harm to China during the period between 1900 and 1945."