Sudan is experiencing its worst floods in living memory. The International Federation of the Red Cross and Red Crescent Societies said in a statement last week the floods could affect some 2.4 million people across 16 of Sudan's 26 states.

Sudanese Interior Minister Zubeir Bashir Taha warned the situation was almost critical, predicting heavier rains in the coming days or weeks.

"The levels are now fluctuating between alert and critical. We haven't as yet exceeded the critical level. We have exceeded the alert level," the minister told Reuters earlier this week.

Taha said there is no immediate shortage of tents or food and 25,000 families have been provided shelter so far.

"We can go up to about 100,000. If we go above 100,000 families in need of shelter it will be a certain crisis," he said.

Most of the 55 dead and 125 injured have been in central, eastern and southeastern Sudan, according to Ali.

"Nearly 25,000 homes have been completely destroyed and 20,000 homes partially affected," he said, adding that 130 government buildings, including schools, had collapsed.

Ali said the rains had also affected parts of south Sudan.

Major roads to some parts of the country and bridges have either been washed away or disabled.

Police helicopters continue to air drop supplies to people stranded in places inaccessible by road, including villages in northern Sudan, which was among the worst hit regions during last year's flooding.

"We definitely need large helicopters because fixed wing we don't have air strips and roads are inaccessible," the interior minister said.