Ghana's government says 20 people have been killed in flooding in the Northern, Upper East and West regions of the country. Thousands of others have been affected. Heavy rainfall in late August and September has caused flooding in Ghana's Upper East, Upper West, and Northern regions. Ghana's government has declared a state of emergency in the affected areas. A government-led rapid assessment team including representatives from USAID, United Nations (U.N.) agencies and non-governmental organisations was visiting the areas worst hit on Tuesday (September 18). According to the government, the flooding has killed 20 people and affected about 260,000 others. Many displaced families have found shelter in school buildings and churches. The flooding has also caused the collapse of nine bridges, destroyed water supply systems, schools, roads and an undetermined amount of crops and livestock. The United Nations said severe floods across West Africa had impacted 500,000 people in 12 countries, wiping out crops and homes. The countries are Burkina Faso, Gambia, Ghana, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone and Togo. About half of those affected live in Ghana, the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said. The International Federation of the Red Cross and Red Crescent Societies said earlier this month at least 87 people had been killed in flooding in West Africa, mostly in Nigeria, in the past two months. Often prone to drought, East and West Africa frequently endure floods in August and September, the end of the rainy season. Hailstorms and landslides have compounded the problems. While thousands of families have fled to flimsy shelters, the risk of water-borne diseases such as cholera and malaria was growing.