Bangladesh's Prime Minister Sheikh Hasina has issued a new call for Myanmar to take back some 420,000 Rohingya Muslims who have fled violence in the Buddhist-dominated country.

Hasina, speaking to Bangladeshi activists in New York where she is attending the United Nations General Assembly, also called for greater international pressure on Myanmar over the new crisis which has unfolded in the past three weeks, media reports said.

“We have told Myanmar, they are your citizens, you must take them back, keep them safe, give them shelter, there should not be any oppression and torture,” she told a meeting late Tuesday in New York.

The Bangladeshi prime minister said Dhaka was making diplomatic efforts to persuade Myanmar to take back the refugees.

“But the Myanmar government is not responding to the calls. Rather, Myanmar is laying landmines along the border to stop the return of Rohingyas to their homeland,” she said.

At a meeting of Islamic nations on the sidelines of the UN assembly, Hasina said Yangon was spearheading a state-sponsored propaganda campaign to call the Rohingya 'Bengalis', adding that they must be given Myanmar citizenship.

Hasina sought “urgent humanitarian assistance” from Muslim nations to cope with the influx of Rohingya who have fled what she called “ethnic cleansing”, the state BSS news agency reported. “It is an unbearable human catastrophe. I have visited them and listened to the stories of their grave sufferings, particularly of women and children,” she said.

“I would like you all to come to Bangladesh and hear from them about the atrocities in Myanmar,” she added.

Growing humanitarian crisis

The majority of of the refugees are women and children. While Bangladesh has earned international praise for opening its doors to the Rohingyas, aid agencies have warning of a growing humanitarian crisis as authorities struggle to provide even basic facilities for the new arrivals.

The 420,000 now in makeshift shelters around the border town of Cox's Bazar have added to about 300,000 Rohingya who moved into camps in the region following earlier waves of violence in Myanmar.

Aid officials said relief camps were reaching full capacity. Large numbers of refugees required immediate medical attention as they were suffering from respiratory diseases, infection and malnutrition, aid workers said, adding that the existing medical facilities in the border area were insufficient to cope up with the influx and more aid and paramedics were needed.

Will take back verified refugees only: Suu Kyi

Myanmar's de-facto leader Aung San Suu Kyi said in a speech hours earlier that the country would take back verified refugees. Myanmar considers the Rohingya illegal migrants from Bangladesh and refuses them citizenship, even though many have lived there for decades.

Aung San Suu Kyi said in her much-anticipated address that she does not fear global scrutiny over the Rohingya crisis, pledging to hold rights violators to account and to resettle some of the 410,000 Muslims who have fled army operations in her country. She offered no concrete solutions to stop what the UN calls "ethnic cleansing". Amnesty International said that the Nobel peace prizewinner was "burying her head in the sand" by ignoring army abuses.

In a 30-minute televised speech, she said that Myanmar stood ready "at any time" to repatriate refugees in accordance with a "verification" process agreed with Bangladesh in the early 1990s. Those "verified as refugees" will be "accepted without any problems and with full assurance of their security and access to humanitarian aid", Suu Kyi said.

It was not immediately clear how many Rohingya would qualify to return. Myanmar's government previously said it will not take back people linked with "terrorists" and suggested that many of those who fled had set fire to their own villages before leaving.

Suu Kyi insisted that army "clearance operations" finished on September 5 without any further militant attacks. But AFP reporters have seen homes on fire in the days following September 5, while testimony from refugees arriving in Bangladesh suggests army operations have continued.

"If nothing has happened since September 5th, and all the Rohingya have left, who burned them?" Phil Robertson of Human Rights Watch told AFP.

Rights monitors and Rohingya refugees allege the army — often flanked by ethnic Rakhine mobs — systematically torched their villages. Around 170 Rohingya villages have been razed to the ground, the government says, nearly 40 per cent of the total in Rakhine.

Suu Kyi said the "majority of Muslims in the Rakhine state have not joined the exodus... more than 50pc of the villages of Muslims are intact".