Amnesty International has accused Myanmars military chief and other top brass of crimes against humanity for overseeing a "systematic" attack against Rohingya Muslims, calling for their prosecution at the International Criminal Court. More than 700,000 Rohingya Muslims were forced to flee Rakhine state after a military crackdown that the United Nations has said amounts to "ethnic cleansing".  A new report from Amnesty said army commander-in-chief Min Aung Hlaing and 12 other senior military and security officials oversaw an orchestrated campaign of violence in the restive state where the Rohingya have been historically marginalized. "The ethnic cleansing of the Rohingya population was achieved by a relentless and systematic campaign in which the Myanmar security forces unlawfully killed thousands of Rohingya, including young children," said the report. "The bulk of these crimes were not the actions of rogue or out-of-control soldiers or units," it added, rejecting previous claims by the military that some soldiers may have broken the rules of engagement.  It also accused security forces of sexual violence, torture, forced displacement and burning markets and farmland that starved communities and forced them to flee. "These crimes amount to crimes against humanity under international law, as they were perpetrated as part of a widespread and systematic attack against the Rohingya population," the report said.  The report said some senior military figures and border guard police oversaw units that directly carried out alleged atrocities, while others knew of subordinates actions and failed to prevent, stop or punish the crimes. The 186-page report is the most detailed account of the crisis yet and follows fresh sanctions from the European Union this week against seven security officials accused of serious crimes including sexual violence and killings. Min Aung Hlaing was not hit by the sanctions but six people on the EU list are named in the Amnesty report, including Major General Maung Maung Soe, the former head of the western command in Rakhine.  In a rare move, Myanmars military said this week he had been sacked for "weakness" in his role. But some said it was a piecemeal gesture.  "They are now grasping for ways to draw a line under international pressure," Aaron Connelly, director of the Southeast Asia project at the Lowy Institute in Australia, told AFP.  "But none of these attempts are likely to work, short of prosecutions for crimes against humanity and the eventual return of large numbers of Rohingya to Rakhine State under improved legal and humanitarian conditions." Amnesty called for the United Nations Security Council to refer the reports findings to the International Criminal Court (ICC).