WATCH: Floods and landslides devastate South Kivu in DRC

The floods and landslides caused by heavy rains on Thursday in South Kivu, in the east of the Democratic Republic of Congo, have left at least 394 dead whose bodies have been found, according to a new report released on Sunday by an administrative official.

The official, Thomas Bakenga, administrator of Kalehe territory, where the affected villages are located, had reported on Saturday that at least 203 people had died.

He told local media that it was not possible to evaluate the full extent of the human losses and material damage.

The torrential rains caused rivers to overflow from their banks, submerging villages, washing away houses and devastating fields.

At the end of Friday's council of ministers, Kinshasa announced the sending of a "government mission to support the provincial government in managing this disaster". It declared a day of national mourning on Monday.

Congolese doctor and Nobel Peace Prize winner Denis Mukwege, whose clinic is located in Bukavu, the capital of South Kivu, said Saturday he had sent a team of surgeons, anaesthetists and technicians to the area to "provide the population with emergency medical aid".

Doctors Without Borders (MSF) also said it had sent an emergency team on Saturday.

The disaster comes two days after floods killed at least 131 people and destroyed thousands of homes in neighbouring Rwanda.

Experts say extreme weather events are happening with increased frequency and intensity due to climate change.