Images shared online, which Reuters was not immediately able to verify, showed entire neighbourhoods flooded with muddy water and roads ripped apart by sinkholes.

One video appeared to show a major highway cut in half by a giant hole that had swallowed several vehicles in the Mont-Ngafula district.

Onlookers in raincoats crept to the edge to peer into the chasm.

“We are already at around 50 deaths and that is not yet final,” Kasongo said.

The prime minister and provincial governor are visiting flooded areas, and local officials are expected to meet representatives of the interior ministry and other state bodies to address the emergency, a representative of the governor’s office said.

Once fishing villages on the banks of the Congo River, Kinshasa has grown into one of Africa’s largest megacities with a population of around 15 million.

Poorly regulated rapid urbanisation has made Kinshasa increasingly vulnerable to flash floods after intense rains, which have become more frequent due to climate change.

At least 39 people died in Kinshasa in 2019 when torrential rain flooded low-lying districts, and some buildings and roads collapsed.

In addition to damaged infrastructure, each day of flooding in Kinshasa costs households a combined US$1.2 million due to the large-scale transport disruption, according to a 2020 World Bank paper.