“The loss, in terms of property and lives, is really huge,” Kinshasa vice governor Neron Mbungu told AFP, stressing that the death toll was preliminary.
He said the dead included a child who was electrocuted, adding that three of the city’s 26 districts were particularly hard-hit.
Fatal floods are frequent in Kinshasa, Africa’s third-largest city with around 10 million people. Experts say the city’s substandard building practices and large slum areas give little protection, leading to relatively high death tolls.
President Felix Tshisekedi visited one of the worst-affected areas at the end of the day and was heckled by a group of young people, who told him to “come and put the concrete back on our street”.
Mbungu said a bridge connecting the districts of Lemba and Ngaba had collapsed and another was destroyed in the district of Kisenso.
In Lemba, an AFP journalist saw a hole about 10 metres (30 feet) deep and 20 metres across where a road had been swept away.
Lemba mayor Jean Nsaka said a drainage ditch had given way under the pressure of the water and the road had been engulfed.
“More than 300 homes have been flooded. There are many houses which have been destroyed,” Nsaka said.
Flood deaths in Kinshasa are “linked to overpopulation (and) building on land which is vulnerable to flooding”, Roger-Nestor Lubiku, former head of the Geographical Institute of Congo (IGC), told AFP.
In January last year, around 50 people were killed in landslides and floods and after houses collapsed following just one night of heavy rain in the capital.
Kinshasa’s population has doubled in less than two decades, with many people living in precarious dwellings.
“Eighty percent of the losses are caused by unauthorised constructions,” said Mbungu, the city’s vice governor, of the latest flooding.
“People are stubborn and do not respect the building regulations. Even if the state says they shouldn’t build there, they build. And you can see the consequences today.”
Elsewhere in the vast country this year’s rainy season has claimed seven lives in floods and landslides in the far eastern South Kivu region, local official Seth Wenga said.