Myanmar's Information Ministry says nine policemen were killed in an attack in the western state of Rakhine by the increasingly active Arakan Army rebel group.

The ministry's website said 60 Arakan Army insurgents on Saturday night attacked the police post, which was safeguarding question and answer sheets from the national high school matriculation examination.

The Arakan Army, which is aligned with Rakhine's Buddhist population, seeks autonomy for the region. Rakhine is better known as the site of a brutal counterinsurgency campaign by the military against the Muslim Rohingya minority, causing more than 700,000 to flee to neighboring Bangladesh. Attacks on police by Rohingya insurgents triggered the crackdown.

The government declared the Arakan Army a terrorist organization after it killed 13 police officers and wounded nine in Jan. 4 attacks.