The worst floods for years have killed at least 150 people and uprooted more than a million others in eastern Africa, aid workers said on today.
Somalia, Ethiopia, Kenya and Rwanda have all been hit by driving rains and rising waters in recent weeks that have destroyed homes and cut off some of the world's poorest people.
Somalia has been hardest hit, and efforts to deliver aid are proving difficult. Some reports say more than 100 people have died there, a few eaten by crocodiles swept from rivers into villages.
"Many communities, especially in the Juba region, are still totally isolated," said Christian Balslev-Olesen, representative of the UN children's charity Unicef for Somalia.
"We have flown over these villages in planes and you cannot see anyone. You ask yourself, where did all these people go?"
Unicef says 350,000 Somalis have been directly affected, but Mr Balslev-Olesen said that was a conservative estimate.
Since October 1st, most regions of the country have already had more than 300 per cent of their normal rainfall, submerging whole villages and reviving bitter memories of the 1997-1998 floods that killed at least 2,100 Somalis.
Mr Balslev-Olesen said it appeared some lessons had been learned from that disaster, with tonnes of food pre-positioned near particularly vulnerable settlements. He said the international community had also been quicker to charter helicopters to reach cut off villages.
More than 80 people have been killed in floods in remote parts of Ethiopia bordering Somalia, the UN says. Nearly a quarter of a million people have lost their livelihoods there, and about a third of those have lost their homes as well.
In Kenya, parts of the coasts and remote northeast have been devastated. Three huge refugee camps for Somalis fleeing violence at home have been cut off from the outside world.
At the most flooded camp, Ifo, refugees had to carry what remained of their meagre belongings through the water to temporary shelters on higher ground 20 km away.
A Red Cross spokeswoman said 41 Kenyans had died and that nearly three-quarters of a million were directly affected.
In Rwanda, at least 25 people died when a river burst its banks and swamped a northern village. Officials said some bodies were found 20 miles away, and the death toll was expected to rise.