GENEVA (Reuters) - Muslim Rohingyas continue to flee Myanmar to Bangladesh and the United Nations is bracing for possible  further exodus , the U.N. humanitarian aid chief said on Friday. Mark Lowcock, U.N. under-secretary-general for humanitarian affairs, reiterated the world body s appeal for access to the population in northern Rakhine state saying that the current situation was  unacceptable .  This flow out of Myanmar has not stopped yet, it s into the hundreds of thousands of Rohingya (who are) still in Myanmar, we want to be ready in case there is a further exodus,  he told a news briefing in Geneva on Friday.  Half a million people do not pick up sticks and flee their country on a whim.  An estimated 2,000 Rohingya are escaping Rakhine daily for Bangladesh, where 515,000 have fled since violence erupted on Aug. 25, Joel Millman of the International Organization for Migration (IOM) told a separate briefing. 