Violent clashes have been ongoing in the northern part of Myanmar's Rakhine Statesince October 2016. Insurgent attacks by the Arakan Rohingya Salvation Army (ARSA) have led to sectarian violence perpetrated by Myanmar's military and the local Buddhist population against predominantly Muslim Rohingya civilians. The conflict has sparked international outcry and was described as an ethnic cleansing by the United Nations High Commissioner for Human Rights. In August 2017, the situation worsened and hundreds of thousands of refugees fled Myanmar into Bangladesh, with an estimated 500,000 refugees having arrived by 27 September 2017. In January 2019, Arakan Army insurgents raided border police posts in Buthidaung Township, joining the conflict and beginning their military campaign in northern Rakhine State against the Burmese military.