The death toll from a powerful cyclone that pummeled swathes of southern African countries, flooding thousands of square kilometers, on Saturday surged past 600 as diseases stalked tens of thousands of survivors. At least 446 people have died in Mozambique, according to government, adding that 531,000 people had been affected by the disaster and 110,000 were in camps. The storm has also killed scores of people in Zimbabwe, with the U.N. migration agency reporting that 259 people had been killed, while its humanitarian arm OCHA said the death toll was at 154.

The U.N., warning of more suffering, stepped up calls for help in Mozambique as aid agencies struggle to assist tens of thousands of people battered by one of southern Africa's most powerful cyclones. A week after the storm lashed Mozambique with winds of nearly 200 kilometers per hour, survivors are struggling in desperate conditions, some still trapped on roof tops and those saved needing food and facing the risk of outbreaks of disease such as cholera.

The World Food Program (WFP) late Friday night declared the flood crisis a level three emergency, putting it on a par with crises in Yemen, Syria and South Sudan. More than two million people have been affected in Mozambique, Zimbabwe and in Malawi where the storm started as a tropical depression causing flooding, which killed 60 and displaced nearly a million people. Hundreds are still missing in Mozambique and Zimbabwe.