Four days after super cyclone Sidr killed more than 2,400 people in Bangladesh, rescuers were struggling to reach isolated areas along the country's devastated coast and give aid to millions of survivors. "The tragedy unfolds as we walk through one after another devastated village," said relief operator Mohammad Selim in Bagerhat, one of the worst-hit areas. "Often it looks like we are in a valley of death."

Media reports and the chairman of the Bangladesh Red Crescent Society, Mohammad Abdur Rob, said the death toll had already surpassed 3,000, and was likely to go up. The government put the official toll at 2,471 confirmed dead.

"We are trying to reach all the affected areas on the vast coastline as soon as possible, when we will know how many people have exactly died in the devastation," one government official said.

While it will take several days to determine the number of dead and missing, some 3 million survivors who were either evacuated from the low-lying southern coast or whose homes and villages were destroyed will need support, the government said.

Aid workers fear inadequate supplies of food, drinking water and medicine could lead to outbreaks of disease.

Grieving families begged for clothes to wrap around the bodies of dead relatives for burial. In some areas, they put corpses in mass graves.

Reuters reporters in the affected districts said bodies were being discovered by the hour in the rivers and paddy fields and under piles of debris.