The United Nations has denounced Burma‘s operations against Rohingya Muslims as a “textbook example of ethnic cleansing”.

The UN High Commissioner of Human Rights said the “brutal security operation” in Rakhine state was “clearly disproportionate and without regard for basic principles of international law”.

Zeid Ra’ad al-Hussein told the United Nations Human Rights Council in Geneva that more than 270,000 people had fled to Bangladesh, with more trapped on the border, amid reports of the burning of villages and extrajudicial killings.

“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. “The situation seems a textbook example of ethnic cleansing.”

Rohingya crisis: Muslim village burnt to the ground

The military campaign began on 25 August, when Rohingya insurgents attacked dozens of Burmese police and paramilitary posts in what they said was an effort to protect their ethnic minority from persecution by security forces in the majority Buddhist country.

In response, the military unleashed what it called “clearance operations” to root out Arakan Rohingya Salvation Army militants.

Almost 300,000 refugees have since fled over the border into Bangladesh’s border district of Cox’s Bazar, where they have given horrific accounts of the violence.

Survivors said the military was targeting civilians with shootings and burning of Rohingya villages in an apparent attempt to purge Rakhine state of Muslims.

Satellite images have supported their accounts, while the bodies of killed Rohingya have been pulled from rivers and others have allegedly been burned.

Some Burmese officials have claimed civilians are setting fire to their own homes but Mr al-Hussein called the claims a “complete denial of reality”, which he said was doing “great damage to the international standing” of the government.

He said he was “appalled” by reports of Burmese troops planting landmines along the border and also warned India against the potential mass deportations of Rohingya families, who have received death threats and been declared illegal by local officials in Jammu.

Rohingya refugees – in pictures Show all 15 1 /15 Rohingya refugees – in pictures Rohingya refugees – in pictures A young girl and a baby wade through mud after arriving in Whaikhyang, Bangladesh from Burma on 10 September Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya refugees walk through a camp in Whaikhyang, Bangladesh after arriving from Burma Dan Kitwood/Getty Images Rohingya refugees – in pictures A young Rohingya refugee gathers firewood after arriving in Whaikhyang, Bangladesh from Burma Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya refugees wait for sacks of rice to be distributed in Whaikhyang, Bangladesh Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya Muslim refugees arrive on a boat in Whaikhyang, Bangladesh after crossing from Burma on 8 September Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya Muslim refugees react after being re-united with each other after arriving in Whaikhyang, Bangladesh on a boat from Burma Getty Rohingya refugees – in pictures Rohingya Muslim refugees walk along the remains of a road after arriving in Whaikhyang, Bangladesh on a boat from Burma Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya Muslim refugees wade through water after arriving in Whaikhyang, Bangladesh by boat from Burma Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya Muslim refugees wade through water after arriving in Whaikhyang, Bangladesh by boat from Myanmar Dan Kitwood/Getty Images Rohingya refugees – in pictures Rohingya Muslim refugees stand in the rain after arriving in Whaikhyang, Bangladesh by boat from Burma Dan Kitwood/Getty Images Rohingya refugees – in pictures Indian children hold placards and shout slogans during a protest against the alleged persecution of the Rohingya Muslims in Burma EPA/Raminder Pal Singh Rohingya refugees – in pictures Supporters of the Difa-e-Pakistan Council (DPC), an Islamic organisation, listen to their leaders' speeches against Burma's persecution of Rohingya Muslims, during a demonstration in Karachi Reuters/Akhtar Soomro Rohingya refugees – in pictures Hundreds of Iranians take part in a protest against violence in Myanmar after weekly Friday prayers, in Tehran EPA/Abedin Taherkenareh Rohingya refugees – in pictures Indonesian Muslim activists hold placards and shout slogans during a protest against the alleged persecution of the Rohingya minority in Magelang, Central Java, Indonesia EPA/Ali Lutfi Rohingya refugees – in pictures Members of an Islamic organisation shout slogans against the Burma government during a protest in Dhaka, Bangladesh EPA

Mr al-Hussein said he warned last year that the pattern of “gross violations” against Rohingya suggested a systematic attack that could amount to crimes against humanity, but that the lack of access for investigators meant the current situation could not be fully assessed.

Human rights organisations have been warning over the plight of the ethnic minority for decades amid worsening persecution.

The Burmese government has long considered Rohingyas to be foreign nationals from Bangladesh, despite their population numbering over one million and making up a large portion of the country’s Muslim population.

A 1982 law excluded Rohingya from gaining Burmese citizenship, making them one of the largest stateless populations in the world and leaving them at the mercy of systematic abuse including restrictions on freedom of movement, work, privacy, marriage and access to basic health services and education.

The Bangladeshi government has offered a plot of land for a new refugee camp as men, women and children continue to pour across the border, with the two existing settlements overcrowded.

The Dalai Lama, the Buddhist spiritual leader of Tibet, said those carrying out the campaign “should remember Buddha,” adding: “I think in such circumstances Buddha would definitely give help to those poor Muslims.”

He said he had delivered the message to Burma’s leader, Aung San Suu Kyi, several years ago at a meeting of Nobel Peace Prize laureates.

While Burmese Buddhists also follow the teachings of the Buddha, they have a different religious tradition to Tibetans and do not recognise the Dalai Lama as their spiritual leader.