More bodies were being recovered on Monday, adding to the scores of others that were wrapped in bags and piled into mass graves over the weekend, local civil society sources said.

The villages of Bushushu and Nyamukubi in Kalehe territory, South Kivu province, were inundated on Thursday after days of torrential rain triggered landslides and caused rivers to break their banks.

At least 176 people were reported dead on Friday as humanitarian workers dug through the remains of the flattened villages to recover mud-caked bodies from the debris with hundreds of people still missing.

South Kivu governor Theo Ngwabidje Kasi told Reuters on Monday the death toll now stood at 401. He did not provide further details.

“It is the worst flood we have ever had,” civil society representative Christian Zihindula Bazibuhe said, adding that bodies were still floating on Lake Kivu.

The central government in Kinshasa has not yet communicated a death toll. It has sent a delegation to Kalehe and declared Monday a day of national mourning.

The United Nations’ humanitarian agency OCHA said on Sunday that at least 270 deaths had been confirmed so far with more than 300 people still unaccounted for.

Around 3,000 families have lost their homes, it added.

Warming temperatures due to climate change are increasing the intensity and frequency of Africa’s rains, according to United Nations climate experts.

This can increase the destruction wrought by the floods and landslides that were already common in South Kivu. Poor urban planning and weak infrastructure also make it more vulnerable to such events.

“The government does not consider environmental issues a priority,” said Congo climate activist Josue Aruna, denouncing the lack of response plans.

On Saturday, U.N. Secretary General Antonio Guterres described the floods as “another illustration of the acceleration of climate change” and the impact on nations “that have contributed nothing to global warming”.

More than 8,800 people have been affected by the floods in Congo, according to the Congolese Red Cross that said of the 274 people buried so far, 98 were women and 82 were children.

Congolese Nobel laureate Denis Mukwege called on the government to ensure victims were given a dignified burial.

“Bury them individually and not in a mass grave,” he Tweeted on Monday.

Heavy rains also triggered flooding and landslides in neighbouring Rwanda last week, killing 130 people and destroying more than 5,000 homes.

(Reporting by Sonia Rolley, Ange Kasongo and Paul Lorgerie; Writing by Sofia Christensen; Editing by Alexander Winning, Alessandra Prentice and Angus MacSwan)