Malala Yousafzai has called on Aung San Suu Kyi to condemn the "tragic and shameful" treatment of the Burma's Muslim Rohingya people following violence that has left hundreds dead.

The Nobel Peace Prize winner, 20, told her fellow laureate that the "world is waiting" for her to act over unrest that has seen tens of thousands of people flee into neighbouring Bangladesh.

Ms Yousafzai's intervention comes after Foreign Secretary Boris Johnson warned Ms Suu Kyi, Burma's de facto leader, that the treatment of the ethnic minority group is "besmirching" the country's reputation.

Burmese security officials and insurgents from the Rohingya are accusing each other of burning down villages and committing atrocities in Rakhine state in the west of the country.

Calling for an end to the violence, Ms Yousafzai said she had been left heartbroken by reports of young children being killed by security forces and urged the Burmese government to grant the group citizenship.

She wrote: "Over the last several years, I have repeatedly condemned this tragic and shameful treatment.

"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."

Almost 400 people have died in the recent unrest, with the Burmese military accused of committing crimes against humanity by campaigners.

Ms Yousafzai wrote: "Stop the violence. Today we have seen pictures of small children killed by Myanmar's security forces. These children attacked no-one, but still their homes were burned to the ground.

"If their home is not Myanmar, where they have lived for generations, then where is it? Rohingya people should be given citizenship in Myanmar, the country where they were born."

On Saturday Mr Johnson sent a message to Ms Suu Kyi, who won the Nobel Peace Prize for her pro-democracy activism, to use "all her remarkable qualities" to end the violence.

He said: "Aung San Suu Kyi is rightly regarded as one of the most inspiring figures of our age but the treatment of the Rohingya is alas besmirching the reputation of Burma.

"She faces huge challenges in modernising her country. I hope she can now use all her remarkable qualities to unite her country, to stop the violence and to end the prejudice that afflicts both Muslims and other communities in Rakhine.

"It is vital that she receives the support of the Burmese military, and that her attempts at peacemaking are not frustrated. She and all in Burma will have our full support in this."

According to the UN's refugee agency an estimated 73,000 people have crossed the border into Bangladesh since violence flared on August 25, leaving relief camps near full capacity.

Ms Yousafzai, who narrowly avoided death in 2012 after being shot in the head by the Pakistani Taliban for her outspoken campaigning over girls' rights to an education, called for more countries to offer the Rohingya food, shelter and schooling.

Awarded the Novel Peace Prize in 2014, the youngest ever recipient, she recently celebrated a place at the University of Oxford to Philosophy, Politics and Economics (PPE).