Bangladesh announced Thursday it would build one of the world's biggest refugee camps to house all the 800,000-plus Rohingya Muslims who have sought asylum from violence in Myanmar.

The arrival of more than half a million Rohingya Muslims from Myanmar since Aug. 25 has put an immense strain on camps in Bangladesh where there are growing fears of a disease epidemic.

Hard-pressed Bangladesh authorities plan to expand a refugee camp at Kutupalong near the border town of Cox's Bazar to accommodate all the Rohingya.

Two thousand acres (790 hectares) of land next to the existing Kutupalong camp were set aside last month for the new Rohingya arrivals. But as the number of newcomers has exceeded 500,000 -- adding to 300,000 already in Bangladesh, another 1,000 acres has been set aside for the new camp.

Mofazzal Hossain Chowdhury Maya, minister for disaster management and relief, said all the Rohingya would eventually be moved from 23 camps along the border and other makeshift camps around Cox's Bazar to the new zone.

"All of those who are living in scattered places... would be brought into one place. That's why more land is needed. Slowly all of them will come," the minister told AFP, adding families were already moving to the new site known as the Kutupalong Extension. The minister said two of the existing settlements have already been shut down.

This week Bangladesh reported 4,000-5,000 Rohingya were crossing the border daily after a brief lull in arrivals, with 10,000 more waiting at the frontier.

The United Nations has praised Bangladesh's "extraordinary spirit of generosity" in opening up its borders. But UNICEF chief Anthony Lake and U.N. emergency relief coordinator Mark Lowcock said in an appeal for $430 million to provide aid that "the needs [of the Rohingya] are growing at a faster pace than our ability to meet them".

"The human tragedy unfolding in southern Bangladesh is staggering in its scale, complexity and rapidity," they said in a statement calling the Rohingya crisis "the world's fastest developing refugee emergency."

The United Nations has said the Myanmar army campaign could be "ethnic cleansing" while military leaders have blamed the unrest on Rohingya.

While the worst of the violence appears to have abated, insecurity, food shortages and tensions with Buddhist neighbors are still driving thousands of Rohingya to make the arduous trek to Bangladesh. Bangladesh has made the journey even more difficult with a clampdown on boats running refugees across the Naf river that separates the two countries.

Authorities have destroyed at least 30 wooden fishing vessels whose captains are accused of smuggling Rohingya and illegal drugs into the country, officials said yesterday. The boatmen were caught in possession of about 100,000 "yaba" pills, an illegal stimulant popular in Bangladesh, said a border guard official.