More than a quarter of a million Rohingya people are on the move or have already left Myanmar for neighbouring Bangladesh in what's being called a classic case of ethnic cleansing by the United Nations.
While Rangoon has defended its role in the process of removing people from the region which abuts Bangladesh, aid workers say the army and radical Buddhists are moving village to village, forcing the Muslim Rohingya to leave and torching buildings.
United Nations High Commissioner for Human Rights Zeid Ra'ad Al Hussein has warned that a brutal security operation is under way in Rakhine State.
According to the UNHCR, in less than three weeks more than 270 000 people have fled to Bangladesh, three times more than the 87,000 who fled the previous operation which began after insurgents attacked Myanmar soldiers and police at 30 different posts.
The UN says the response from Myanmar has been disproportionate and counter to international law.
"We have received multiple reports and satellite imagery of security forces and local militia burning Rohingya villages," he said, "and consistent accounts of extrajudicial killings, including shooting fleeing civilians. I am further appalled by reports that the Myanmar authorities have now begun to lay landmines along the border with Bangladesh, and to learn of official statements that refugees who have fled the violence will only be allowed back if they can provide proof of nationality," said the commissioner during a speech at the UN on September 11.
"Given that successive Myanmar governments have since 1962 progressively stripped the Rohingya population of their political and civil rights, including citizenship rights – as acknowledged by Aung San Suu Kyi's own appointed Rakhine Advisory Commission – this measure resembles a cynical ploy to forcibly transfer large numbers of people without possibility of return," Al Hussein said.
The Rohingya occupy a region cut off from the rest of Myanmar by a mountain range. This has had the effect of splitting the country along geographical lines. The situation has been worsened by fundamentalists returning from the wars in Libya, Syria and Iraq and inflaming tensions in Myanmar.
The last straw for the government was the multi-pronged attack on its security forces which led directly to the latest violence.
"Last year I warned that the pattern of gross violations of the human rights of the Rohingya suggested a widespread or systematic attack against the community," said Al Hussein.
"Because Myanmar has refused access to human rights investigators the current situation cannot yet be fully assessed, but the situation seems a textbook example of ethnic cleansing."
The Bangladeshi government is under pressure to allow the more than 250,000 refugees into their territory. But Dhaka is already facing its own radical Islam and has been slow to respond to UN requests.
India has also begun to deport Rohingyas. About 40,000 Rohingya live in India but fewer than half have received proper documentation.