Heavy rains have been drenching Africa's Sahel region since June and the latest victims in Niger come on top of at least 217 people who have died across the country in that time, according to authorities.

More than 350,000 people have been affected and last week rising floodwaters nearly cut off the capital Niamey from the rest of the country before retreating.

The latest deaths occurred on Friday in the city of Maradi, the country's economic capital whose eponymous region that has been one of the areas most affected by the rains.

"We have registered 15 human lives lost, we have also registered injured and heavy material damage", regional governor Issoufou Mamane told public television.

Friday saw 150 millimetres (six inches) of water fall on the city in the space of 90 minutes, local television said.

Images broadcast on television showed water racing through the streets, touching off landslides and collapsing homes as it carried off cars, motorcycles and trees.

Drinking water and electricity supplies have been affected in some areas, according to broadcasters.

The downpours have also disturbed traffic on the main route linking Maradi to the city of Zinder.

Niger's rainy season normally lasts from June to September and consistently brings a heavy death toll.

In 2022 there were 195 deaths and 400,000 people affected.