Myanmar has refused to give UN investigators access to the country and blocked an independent and impartial investigation after destroying at least 319 villages, said Marzuki Darusman, the chairman of the UN's Independent Fact-finding Mission on Myanmar.
Darusman urged Rohingya Muslims not to return without adequate guarantees for human rights protection.
"People continue to flee. The number of new arrivals in camps in Bangladesh is continuing at a pace of up to 1,000 persons per week," Darusman told the UN human rights council in Geneva after conducting over 600 in-depth interviews with victims and witnesses of alleged human rights violations and abuses.
Both the Myanmar military and civilian authorities have effectively labeled the whole Rohingya population as Bengali "illegal immigrants" and "extremist terrorists", he said.
"It is critically important for the displaced people not to be returned without adequate guarantees for human rights protection in place. Otherwise, we could be laying the groundwork, not for solutions, but for another repeat experience," he added.
In a report, UN investigators said such violations may have constituted crimes against humanity.