The mass killings of Rohingya in Myanmar's Rakhine State constitute genocide and top military commanders should face prosecution for crimes against humanity, a team of United Nations investigators has concluded.After an eruption of intense violence last August, hundreds of thousands of Rohingya, members of a Muslim minority group, fled Buddhist-majority Myanmar to escape horrific massacres, mass rapes and the torching of their villages.The U.S.andU.N. have denounced the attacks on the Rohingya as ethnic cleansing. Now, the U.N. investigators are describing it as genocide and calling for accountability.It's not known how many Rohingya have died as the result of the attacks, but the U.N. team says an estimate of 10,000 deaths is "conservative."The crimes are "shocking for their horrifying nature and ubiquity" and "for the level of denial, normalcy and impunity that is attached to them," the U.N. researchers concluded. "Many of these violations undoubtedly amount to the gravest crimes under international law."Their report names six military officials, including the country's commander-in-chief, as "priority subjects" for prosecution on charges of genocide, crimes against humanity and war crimes. Investigators have prepared a longer list of names that has not yet been released.The report also indicates that civilian leadership, including de facto leader Aung San Suu Kyi, did not directly participate in the genocide, but "contributed" to the crimes through inaction, denial, destruction of evidence and interference with outside investigation.The findings "come as no surprise to those who've listened to the victims' stories or seen the evidence left behind," Michael Sullivan reports for NPR.The U.N.'s Independent International Fact-Finding Mission on Myanmar released its report on Monday. A longer version is set to be released in September.The mission was not granted access to Myanmar to investigate the attacks. Instead, investigators relied on satellite imagery, photographs and videos and "875 in-depth interviews with victims and eyewitnesses."The brutal attacks on Rohingya did not come out of nowhere, the report forcefully argues."What happened on 25 August 2017 and the following days and weeks was the realisation of a disaster long in the making," the investigators concluded.They describe a system of discrimination against Rohingya that dates back decades, steadily marginalizing and "othering" the members of the group while depriving them of basic legal rights."The result is a continuing situation of severe, systemic and institutionalised oppression from birth to death," the investigators say. It grew worse in 2012, after a hate campaign against the Rohingya led to waves of violence.In 2016, a small offensive by the poorly equipped Rohingya militant group called the Arakan Rohingya Salvation Army prompted a crackdown on the Rohingya that included torture and mass rape. Then, in August 2017, ARSA launched coordinated attacks on security force outposts, killing 12 security personnel, the U.N. investigators say."The security forces' response, starting within hours, was immediate, brutal and grossly disproportionate," the report states.It goes on to describe, in understated terms, the kinds of atrocities that human rights groups and journalists have long been documenting from the fleeing Rohingya survivors: gang rapes, arson attacks, indiscriminate shooting, deaths by bladed weapons.The arson attacks "disproportionately affected the elderly, persons with disabilities and young children, unable to escape," the report states. "In some cases, people were forced into burning houses, or locked into buildings set on fire."Soldiers gang-raped women, sometimes raping them with knives and sticks, often in public to maximize their humiliation. Many women were injured or killed during those rapes. Children were killed, maimed and raped, as well, and there were "credible reports" of the rape and sexual torture of men and boys.The Tatmawdaw, Myanmar's military, also systematically attacked civilians in other parts of Myanmar, including in Kachin and Shan states, the U.N. investigators said."The Tatmadaw acts with complete impunity and has never been held accountable," the report states. Myanmar's court system is not independent enough to provide accountability, and the government is "unable and unwilling" to prosecute these crimes, putting the burden on the international community, the investigators concluded.Other armed groups — including local police, border guard police, militias and monks — also participated in atrocities, but the report emphasizes that the soldiers were acting under a chain of command that allows leaders to be held accountable.The "non-exhaustive list" of subjects for prosecution focuses on the top military leaders involved in the operations in Rakhine State. It includes the man who is the military's commander in chief, Senior-General Min Aung Hlaing, and five other commanders.One of those commanders, Lt. Gen. Aung Kyaw Zaw, has already been singled out for U.S. sanctions as punishment for the attacks on Rohingya. Two of the U.N.'s other "priority subjects" are brigadier generals who lead two light infantry divisions — the 33rd and the 99th — that were collectively targeted by U.S. sanctions. Three other commanders, who weren't named in the U.N. report, were also sanctioned.As NPR's Colin Dwyer reported this month, "The Trump administration's sanctions were quickly criticized for aiming at the middle tiers of Myanmar's security apparatus and leaving its highest rungs untouched. The official notice also avoided using strong labels such as 'genocide' to describe the military's actions, referring only to 'serious human rights abuses.' "The U.N. report, on the other hand, goes straight to the top.However, the fact-finding mission — led by Indonesia's former attorney general, Marzuki Darusman — can recommend only that an international tribunal investigate and prosecute the crimes; the mission cannot itself determine guilt or impose sanctions."Unless impunity is addressed, and all ranks within the security forces are held accountable for their past, current and future actions, similar outbreaks of violence and associated atrocity crimes can be expected to continue, with further devastating domestic and regional impact," the report states."The mission has sent an advance copy of the report to the Myanmar government, but has received no reply," Lisa Schlein reports for NPR from Geneva. Copyright 2018 NPR. To see more, visit http://www.npr.org/.