China has said it backs Burma's efforts to "safeguard stability" as pressure mounts to end violence which has sent more than 300,000 Rohingya Muslims fleeing to Bangladesh.

Around 370,000 Rohingya refugees have arrived in Bangladesh since 25 August, up from the previous estimate of 313,000, the International Organisation for Migration has said.

The top UN human rights official has denounced Burma, also known as Myanmar, for conducting a "cruel military operation" against the Rohingya, branding it "a textbook example of ethnic cleansing".

The government of the Buddhist-majority country says its security forces are fighting Rohingya militants behind a surge of violence and they are doing all they can to avoid harming civilians.

Video shows Rohingya flee burning villages in Myanmar

Chinese foreign ministry spokesman Geng Shuang said China condemned the violence in Rakhine state.

According to The Straits Times, he said: "We support Myanmar's efforts in upholding peace and stability in the Rakhine state. We hope order and the normal life there will be recovered as soon as possible."

He added: "We think the international community should support the efforts of Myanmar in safeguarding the stability of its national development."

The government says about 400 people have been killed in the fighting in Rakhine State, western Burma.

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

The United States said the violent displacement of Rohingya Muslims showed Burma's security forces were not protecting civilians.

Washington has been a staunch supporter of Burma's transition from decades of harsh military rule, which is being led by Nobel peace laureate Aung San Suu Kyi.

"We call on Burmese security authorities to respect the rule of law, stop the violence, and end the displacement of civilians from all communities," the White House said in a statement.

Burma's foreign ministry said shortly before the US statement was issued that Burma was also concerned about the suffering. It said its forces were carrying out their legitimate duty to restore order in response to acts of extremism.

"The government of Myanmar fully shares the concern of the international community regarding the displacement and suffering of all communities affected by the latest escalation of violence ignited by the acts of terrorism," the ministry said in a statement.

A young girl is squashed as Rohingya refugees wait for sacks of rice to be distributed in Whaikhyang, Bangladesh (Dan Kitwood/Getty Images)

Burma's government regards the Rohingya as illegal migrants from neighbouring Bangladesh and denies them citizenship, even though many Rohingya families have lived there for generations.

Unverified reports from refugees and rights groups paint a picture of widespread attacks on Rohingya villages in the north of Rahkine State by the security forces and ethnic Rakhine Buddhists, who have burned numerous Muslim villages.

Authorities deny the accusations and say nearly 30,000 Buddhist villagers have also been displaced, fleeing to towns to the south.

Rohingya Muslims, fleeing from ongoing military operations in Burma's Rakhine state, try to take food aid at a refugee camp 50 kilometres south of Cox's Bazar, Bangladesh (Getty)

Attacks by a Rohingya insurgent group, the Arakan Rohingya Salvation Army (ARSA), on police posts and an army base in the north of Rakhine State on 25 August provoked the military counter-offensive refugees say is aimed at pushing Rohingya out of the country.

A similar but smaller wave of attacks by the same insurgents last October also led to what critics said was a heavy-handed response by the security forces that sent 87,000 Rohingya fleeing to Bangladesh.

On Sunday, Burma rebuffed a ceasefire declared by ARSA to enable the delivery of aid to thousands of displaced and hungry people in the north of Rakhine state, declaring simply that it did not negotiate with terrorists.

Bangladesh is seeking help as it struggles to cope with the latest influx Rohingya refugees, who have joined more than 400,000 others already there.