Roads turned into gushing rivers and homes swamped by muddy waters: rainstorms and flash floods wreaked havoc across the Kenyan capital Nairobi on Wednesday.

Many parts of the country and the East Africa region have been lashed by relentless rains in recent weeks, as the El Nino weather pattern exacerbates the seasonal rainfall.

Nearly 100,000 people have been displaced in Burundi, while at least 58 people have died in Tanzania and several thousand made homeless.

In Kenya, the UN humanitarian response agency, OCHA, said on Friday that at least 32 people had lost their lives and more than 40,000 were forced from their homes because of the rains and floods.

Kenyan police said their officers on Tuesday saved the life of a five-year-old boy who had been marooned alone by floods in Machakos County south of the capital.

The youngster was airlifted to safety by chopper, the National Police Service said on X, formerly Twitter.

- 'City at a standstill' -

Across Nairobi, images posted by Kenyan media outlets showed trucks, cars and motorbikes stuck in deluges of water.

"The city is at a standstill because most roads are flooded," said Uber driver Kelvin Mwangi.

"We are spending more time on the road because we are having to use longer routes and in some cases we can't get to our destination."

Homes were engulfed in the sprawling Nairobi slum of Mathare, where local media reports said residents were forced to sleep on rooftops overnight.

A picture posted on X by the Kenya Red Cross showed its workers, sometimes waist-high in water, engaged in rescue efforts, as a man carried a young child on his shoulder.

The Athi River, the second longest in Kenya, has burst its banks, the Red Cross said, blocking roads and leaving residents stranded.

It said many parts of Nairobi experienced heavy rainfall overnight, resulting in flash floods in multiple areas.

"Roads and bridges are affected, leading to heavy traffic on major roads," the Red Cross said on X.

"Our response teams are on the ground in most of these areas, evacuating families to safety and providing other life-saving interventions," it added.

Kenya Railways announced it was temporarily suspending commuter train services as a precautionary measure, saying that the heavy rains had affected rail lines.

El Nino often has devastating consequences in East Africa, where late last year more than 300 people died in torrential rains and floods in Kenya, Somalia and Ethiopia.

From October 1997 to January 1998, massive floods caused more than 6,000 deaths in five countries in the region.