Aid agencies warn that unless vital relief supplies reach the survivors soon, the number of those who will die in the coming days could exceed the 3,400 people who died after the devastating storm ripped through southern and central districts on November 15.

Even though a huge military-led aid effort is underway, officials say logistical problems mean that only small amounts of relief are reaching the survivors.

“The only thing we have been given in all the days since the cyclone is two kilograms of rice and 60 taka (less than a dollar) from the local government officials and we have no food and no drinking water," said Mohammad Dulal, 30, from Garjonbunia village, a coastal village that has been washed away by the tidal surge.

Mohammad Dulal, his wife and young son are living on the roadside in a shack made from tree branches and plastic that he scavenged.

"I am very worried about my family. If we do not get help, we will be here for months and the conditions are terrible," he told AFP.

• Water-borne diseases

One of the key problems facing aid agencies now is distributing clean drinking water.

According to UN resident coordinator Renata Lok Dessallien, the lack of fresh drinking water is fuelling fears of an epidemic of water-borne diseases.

"We are concerned about outbreaks of diarrhoea and cholera," she said.

People in the southern-western village of Tafalbari complain that many of them are already suffering from diarrhoea.

"We need clean drinking water urgently. There is none here and we are having to drink dirty water from the river… It is very difficult for our children. They are really suffering," said distraught grandmother Zohanara through her tears.

"We have nothing here, no home, hardly any food and no clean water. We are desperate."

Aid agencies say they are doing their best to tackle the water problem. 

"Support is being strengthened in nutrition, water, sanitation, hygiene and essential medicines," a UN spokesman in Dhaka told the BBC.

"These have been identified as the most vital needs according to assessment teams reporting back from the five main UN agencies in Bangladesh - including the World Food Programme and the UN Development Programme - from the worst affected areas."

The United Nations says that it issued 7.3m water purification tablets (WPTs) and 110,000 jerry cans for carrying safe water in conjunction with the Bangladeshi Department of Public Health and Engineering.

"We have also ensured that an adequate stock of essential medicines is being delivered at districts and sub-districts in the worst affected areas," the UN spokesman said.

• Aid efforts

So far, foreign countries and international donors pledged around $500m for the relief effort.

Bangladeshis from areas not affected by the cyclone are also helping their compatriots.

Farmer Mohammed Emadul Haq, 52, told AFP he had volunteered to help remove tree trunks from blocked canals and waterways.  "We are Bangladeshis, and it's our responsibility to help however we can," he said.

Another volunteer, businessman Swapan Das, said he and a group of colleagues had collected 500,000 taka (7,140 dollars) to create aid packages for victims -- this amount is a fortune in Bangladesh where 40% of the population lives on less than one dollar a day.

Aid efforts can now be seen in affected areas, but with the winter on its way, there are fears that homeless people will be vulnerable to cold weather.

According to the government, over a million houses have been destroyed by the cyclone. Thousands remain missing, feared dead, and at least 280,000 are without shelter. Aid agencies say the real figure could be much more than that.