"Refugees are now squatting in makeshift shelters that have mushroomed along the road and on available land in the Ukhiya and Teknaf areas", said a UNHCR said in a briefing in Geneva.
Moreover, a senior United Nations representative told AFP that more than 1,000 people may already have been killed in Myanmar, mostly Rohingya Muslims.
The United States, a principle backer of Aung San Suu Kyi's civilian government that came to power in Myanmar past year, said there had been shortcomings on the part of Myanmar security forces and the government in dealing with the situation.
"They have killed over 3,000 people there and razed their houses", he told reporters after briefing Dhaka-based foreign diplomats about the government's efforts to provide humanitarian aids to the Rohingyas who have fled to Bangladesh.
And Burmese leader and Nobel Peace Prize victor Aung San Suu Kyi has been fiercely criticised over the crisis.
The military and security forces of Buddhist-majority Myanmar, as well as militia groups, have been widely accused of targeting Rohingya civilians in the new wave of violence.
Most of the Rohingya refugees in India have settled in Jammu and Kashmir, Haryana, Uttar Pradesh, Rajasthan states and Delhi and its adjoining areas.
Mainly Buddhist Myanmar does not recognize its stateless Muslim Rohingya community, labelling them "Bengalis" - illegal immigrants from Bangladesh. The Myanmar government was also asked to "uphold their rights to live and move without fear and discriminations, (conduct) urgent investigations into recent violence against the Rohingya Muslims and hold accountable those involved in these serious crimes".
Number of refugees from Myanmar may top 270000
Former Bangladesh High Commissioner to India Tariq Karim also warned that "the Rohingya issue could throw a spanner in the India-Bangladesh relationship, as PM Sheikh Hasina is under severe pressure on the issue of the violence in Myanmar that has forced out Rohingya".
The mission, to be led by the Malaysian Armed Forces, will leave on Saturday to review the situation in refugee camps.
Ali described actions following the militant attacks on security forces on August 25 as "revenge" by Myanmar troops.
More than 120,000 Rohingya fled over the following five years to Bangladesh and South-East Asia, often braving perilous sea journeys controlled by brutal trafficking gangs.
In an open letter, Tutu told his fellow Nobel Peace Prize victor that it was "incongruous for a symbol of righteousness" to lead a country where violence against the Rohingya is being carried out.
The foreign ministry said Mahmood Ali also requested the global community to help Bangladesh with urgent humanitarian assistance to address the current crisis.
A series of Twitter photos that allegedly showed dead Rohingya were later proved to be unrelated to the current violence, according to a statement posted on Facebook by Suu Kyi's office.
Ali called on the worldwide community to urge the Myanmar government to immediately implement the recommendations of the commission's report "in its entirety".
Reported byBenarNews, an RFA-affiliated online news service.