Flood water covers the ground between rubble where there once use to be houses at an informal settlement in Beira, the fourth largest city in Mozambique, on March 23, 2019. - The man lost his house in Cyclone Idai and he has been rebuilding it the past week. The UN is stepping 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 Tropical Cyclone Idai lashed Mozambique with winds of nearly 200 kilometres (120 miles) 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. (Photo by WIKUS DE WET / AFP)