PURBA SARALIA, Bangladesh - Overburdened relief centres scrambled to help tens of thousands of people and fist fights broke out Wednesday among some survivors of last week's cyclone that killed at least 3,100.

Nearly 2,000 people descended on a government-run relief camp in Purba Saralia, hurriedly set up in a firehouse, where officials only had food for 1,200.

"This is a crisis. I don't have enough food and we have no work," said Lal Mia, a farmer waiting in line.

A few miles away in the village of Basal Bar, fist fights broke out among cyclone survivors as thousands of people who had gathered before dawn waited for rice at a food distribution centre set up by a local aid group.

The coastal area battered by Cyclone Sidr, meanwhile, has been struck with waterborne diseases, Dhaka's Daily Star newspaper reported, quoting local health officials. Two children died of diarrhea in the hard-hit district of Patuakhali, the newspaper reported.

The Health Ministry said it has opened a special desk to monitor any diarrhea outbreaks. It could not immediately confirm the two reported deaths.

"We are concerned about diarrhea," Renata Dessallien, the top UN official in Bangladesh told The Associated Press. "There is no question this will be a problem."

She said water usually gets contaminated by diarrhea-causing bacteria following floods and cyclones.

"But I understand that the health ministry has stock of medicines and the most important thing now is to get the supplies down to the affected areas," she said.

The Disaster Management Ministry, meanwhile, said, in addition to the thousands dead, 1,724 people were missing and 28,188 people had been injured by the storm.

The cyclone also destroyed 458,804 houses and another 665,529 houses have been partially damaged, the ministry said.

Aid agencies and UN officials were visiting the affected areas to assess the damage and the aid need, said Sakil Faizullah, a spokesman for the United Nations Development Program in Bangladesh.

Food, fresh water and temporary shelter still had not reached many of the exhausted survivors six days after the cyclone slammed into the low-lying country.

In a televised speech Tuesday, the country's interim leader, Fakhruddin Ahmed, described the cyclone as "a national calamity" and urged citizens to help the affected people.

The government said international aid worth about $120 million had been promised so far. But relief items such as tents, rice and water have been slow to reach most survivors of the worst cyclone to hit Bangladesh in a decade.

The European Commission announced Tuesday aid of $9.6 million. The American Red Cross said it would provide $1.2 million to help get clean water to the survivors and build emergency shelters.

"The problem is that aid workers need hours to reach these remote areas. Poor communications are also hampering our work," said Anwarul Huq, a spokesman for the Bangladesh Rural Advancement Committee, the country's largest nonprofit development organization.

In many places, aid workers had to clear fallen trees and debris to get to survivors, said Huq, adding that rescuers also were facing a shortage of boats.

The storm, which tore along Bangladesh's southwestern coast on Thursday, left tens of thousands of people homeless and desperate for help.

The official death toll on Tuesday stood at 3,153, said Lt. Col. Main Ullah Chowdhury, spokesman for the army that is coordinating the relief and rescue work.

The Bangladesh Red Crescent Society, the Islamic equivalent of the Red Cross, has suggested the final figure could be around 10,000.