DHAKA (AFP) - Bangladesh restricted the movement of Rohingya refugees on Saturday (Sept 16), banning them from leaving designated areas in the country to which over 400,000 have fled from violence in neighbouring Myanmar.

As Dhaka struggled to cope with the scale of the "unprecedented crisis", dozens of refugees were found in three towns hundreds of kilometres from the Myanmar frontier, stoking fears that thousands of Rohingya Muslims will move from the border region into the the mainland of Bangladesh.

Police said they have now issued an order banning the Rohingya refugees from leaving the areas and camps the government has designated for them in the border district.

"They should stay in the designated camps until they return to their country," Sahely Ferdous, a police spokeswoman, said in a statement.

She said Rohingya were also asked not to take shelter in the homes of their friends or acquaintances and locals have been asked not to rent houses to the refugees.

"They cannot travel from one place to another by roads, railways or waterways," the order said, adding bus and lorry drivers and workers have been asked not to carry the Rohingya.

Police said they have set up check posts and surveillance in key transit points to make sure the refugees don't travel to the other parts of the country.

The restrictions are announced as Bangladesh authorities said they faced an "unprecedented crisis" due to the influx of 409,000 refugees since last month, according to UN figures.

Conditions are already worsening in Bangladesh's southeastern border district of Cox's Bazar where the majority of refugees are living in squalid conditions after fleeing Myanmar's violence-wracked Rakhine state.

Bangladesh has been overwhelmed by the arrivals Rohingya Muslims - the highest number of refugees to have entered the country in decades - since violence erupted in Buddhist-dominated Myanmar's Rakhine state on Aug 25.

Rohingya camps in the border town of Cox's Bazar were already overwhelmed with 300,000 people from earlier waves of refugees before the latest influx.

Most Rohingya, who spent more than a week trekking cross-country from Rakhine to reach the Bangladesh border, have found existing camps overflowing and have instead settled on muddy roadsides.

Many families do not have a shelter over their heads and refugees have been fighting for food and water deliveries.