Desmond Tutu has joined Malala Yousafzai in condemning fellow Nobel laureate Aung San Suu Kyi over the treatment of the Rohingya Muslim minority in Burma.

Mr Tutu called for Ms Suu Kyi’s intervention to help end the crisis.

The South African, a veteran of the fight against apartheid, said Ms Suu Kyi’s “silence” was “too steep” a price to pay for her position and called on her “to be courageous and resilient again”.

More than 160,000 Rohingya Muslims have fled Burma, also known as Myanmar, into neighbouring Bangladesh since an army crackdown was launched on militants from the minority group on 25 August.

There have been widespread allegations of atrocities against civilians, including the beheading of children and burning of villages.

Video shows Rohingya flee burning villages in Myanmar

Ms Suu Kyi, who is Burma’s State Counsellor but spent years under house arrest for opposing the country's military junta, has refused to condemn the army’s actions and blamed “misinformation” for fuelling tensions.

Mr Tutu, who retired in 2010, said he was breaking a vow to “remain silent on public affairs out of profound sadness” for the plight of the Rohingya.

Addressing his “dearly beloved younger sister”, Ms Suu Kyi, in an open letter, Mr Tutu spoke of her previous civil rights work.

But he went on: “The images we are seeing of the suffering of the Rohingya fill us with pain and dread.

“We know that you know that human beings may look and worship differently – and some may have greater firepower than others – but none are superior and none inferior; that when you scratch the surface we are all the same... discrimination doesn't come naturally; it is taught.

“My dear sister: If the political price of your ascension to the highest office in Myanmar is your silence, the price is surely too steep. A country that is not at peace with itself, that fails to acknowledge and protect the dignity and worth of all its people, is not a free country.

“It is incongruous for a symbol of righteousness to lead such a country; it is adding to our pain.

“As we witness the unfolding horror we pray for you to be courageous and resilient again. We pray for you to speak out for justice, human rights and the unity of your people. We pray for you to intervene in the escalating crisis and guide your people back towards the path of righteousness.”

Ms Suu Kyi was awarded the Nobel Peace prize in 1991, which recognised her as Burma’s “modern symbol of freedom” after her decades-long campaign for democracy in the military state.

But despite her ascent in Burmese political life, she has remained largely silent on the Rohingya minority, who are not recognised as citizens of the country.

Though they have been present in Buddhist-majority Burma since pre-colonial times, the Rohingya are often referred to as “Bengalis”, alluding to the myth they are illegal immigrants from Bangladesh.

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

Earlier this week, Malala also called on Ms Suu Kyi to act to “stop the violence” against the minority group.

“Over the last several years, I have repeatedly condemned this tragic and shameful treatment,” she said.

“I am still waiting for my fellow Nobel laureate Aung San Suu Kyi to do the same. The world is waiting and the Rohingya Muslims are waiting.”

She also called on the Rohingya to be given citizenship and for neighbouring countries to support the refugees.