At least 50 villages in Benin have been destroyed by floods, an aid group there says.

"Hundreds of homes, crops, granaries, livestock and poultry have been destroyed by flooding - jeopardising food supply and increasing the risk of malaria and disease from contaminated water," the non-governmental organisation Plan International warned in a communiqué on 17 September.

Plan, one of a handful of NGOs working in the peaceful but impoverished West African state, has visited villages in the Lalo, Klouekanme and Toviklin communes of the Couffo region in Benin.

The NGO says "access is difficult" because torrential rains have surrounded dozens of villages with flood waters, but it has calculated that at least 43,000 people in 50 villages in the Couffo area have been affected, and 200 houses have been destroyed in the Lalo commune.

"Many villages are completely cut off as roads have flooded and telephone lines have been damaged," Plan said. Most people have sought shelter in neighbouring villages, but there is a "high risk of malaria" because most no longer have treated mosquito bed nets. Two children, ages 8 and 9, and one adult are known to have drowned.

Benin, a tiny francophone state of 8.2 million people wedged between Togo to the west and Nigeria to the east, is the latest in a series of West African countries to sound the alarm over flood damage.

Floods have devastated vast areas of sub-Saharan Africa and displaced at least 1 million people across the continent, according to the UN Office for the Coordination of Humanitarian Affairs (OCHA). In West Africa, Burkina Faso, Ghana, Mali, Mauritania, Nigeria, and Togo are among the worst hit countries.

OCHA says heavy rains are likely to continue across West Africa until 24 September. The rainy season usually runs from around July until October.