BBC News Online: World: Africa

Floods threaten Sudan's capital

Khartoum's shanty-dwellers are the most vulnerable

The waters have already submerged whole villages, forcing tens of thousands of people to flee.

The International Federation of Red Cross and Red Crescent Societies (IFRC) said the river had reached its highest level in more than 20 years.

The Nile is running at a higher level than in August 1988, when the river burst its banks, leaving dozens dead and two million homeless.

The organisation says about $800,000 is needed for contingency measures.

Sudanese authorities have warned people downstream of the flooding to be ready to move at short notice, the IFRC said.

In some states, including Darfur, Red Sea and Kassala, there has been significant damage to crops and homes.

"Whole villages and settlements in River Nile and Sinnar states have been submerged," said a statement from the federation's headquarters.

Food and blankets are already being distributed to several areas, but more money is needed to ensure that people have access to clean water, tarpaulins and medical support.

"There are some two million internally displaced people living in shanty towns around Khartoum city and it is they - trapped in poverty - who suffer the most when we get these recurrent floods," said Omer Osman, Secretary-General of the Sudanese Red Crescent.