There have been plenty of detailed reports by journalists and researchers, based on interviews conducted with refugees, which make it hard to dispute that terrible human rights abuses took place at the hands of the security forces.
But many of these reports focussed on the worst cases; there are several media reports about a massacre at one village called Tula Toli. Some Rohingya I interviewed told me they had fled in fear of violence, but had not actually experienced it.
This well-researched figure by MSF suggests the operation conducted by the military was brutal enough to raise the possibility of taking a case to the International Criminal Court (ICC) for crimes against humanity.
The problem would be that Myanmar has not ratified the Rome Statute of the ICC and is not bound to co-operate with it. Bringing a case would require the approval of all five permanent members of the UN Security Council, and China has until now given its full support to the Myanmar government’s handling of the crisis.