The United Nations human rights chief has lashed out at the treatment of the Rohingya in Myanmar which has led to more than 300,000 people fleeing to Bangladesh in the past three weeks, as security forces and local militia reportedly burn villages and shoot civilians.

"The situation seems a textbook example of ethnic cleansing," Zeid Ra‘ad al-Hussein told the UN Human Rights Council in Geneva, noting that the current situation cannot yet be fully assessed since Myanmar has refused access to human rights investigators.

He cited reports of Myanmar authorities laying landmines along the border with Bangladesh and requiring returnees to provide "proof of nationality," an impossibility given that successive Myanmar governments have since 1962 progressively stripped the Rohingya population of their political and civil rights, including citizenship rights.

The latest security operation in Rakhine state follows attacks by militants on 25th August against 30 police posts.

The High Commissioner called the response "clearly disproportionate" and "without regard for basic principles of international law," and said the Government should "stop claiming that the Rohingyas are setting fire to their own homes and laying waste to their own villages."

"This complete denial of reality is doing great damage to the international standing of a government which, until recently, benefited from immense good will," he said.

"I call on the government to end its current cruel military operation, with accountability for all violations that have occurred and to reverse the pattern of severe and widespread discrimination against the Rohingya population," he added.