At least 6,700 Rohingyas were killed in the month after violence broke out in Myanmar in August. <br/><br/>Medecins Sans Frontieres (MSF) says, based on surveys of refugees in Bangladesh, the number is much higher than Myanmar's official figure of 400. MSF said it is the clearest indication yet of the widespread violence by Myanmar authorities. <br/><br/>The Myanmar military blames the violence on terrorists and has denied any wrongdoing. More than 647,000 Rohingya have fled into Bangladesh since August.