HONG KONG — More than 70 people were killed on Friday in clashes between militants and security forces in Rakhine State in western Myanmar, which outside observers called a worrying upsurge of violence in the troubled region.

The dead included at least 12 members of the security forces and at least 59 Rohingya insurgents, according to a statement from the office of Myanmar’s de facto leader, Daw Aung San Suu Kyi. Myanmar’s armed forces said the militants used knives, small arms and explosives in coordinated early-morning attacks on several police and military posts around Buthidaung and Maungdaw, near Myanmar’s border with Bangladesh.

Rakhine is home to about one million Rohingya, a predominantly Muslim minority group that faces repression in Myanmar, where they are largely confined to camps and denied full citizenship rights.

Last October, a group of Rohingya militants killed nine police officers, escalating the level of violence in a long-running conflict. Rohingya and international human rights groups say security forces responded to those attacks by locking down the area and carrying out a far-reaching crackdown, killing hundreds of people and forcing tens of thousands to flee.