More than 170 people have died after heavy rains and flooding in eastern DR Congo’s South Kivu province, officials said Friday, after torrential downpours killed dozens in neighbouring Rwanda.

South Kivu governor Theo Ngwabije said dozens of people were unaccounted for in the Kalehe region, west of Lake Kivu and near the Rwandan border, where the floods also washed away hundreds of homes.

“We have about 176 people dead,” he said while visiting the affected area.

“This toll is provisional,” he said. “We also have about 100 people missing.”

Archimede Karhebwa, the assistant administrator of Kalehe, had earlier told AFP that about 100 people had died, according to a provisional toll.

A day of national mourning will be observed on Monday with flags lowered to half-mast “in memory of the lost compatriots”, the government announced on Friday evening.

Several villages in Kalehe were submerged when rivers burst their banks after heavy rains, he said.

Karhebwa said the floods carried away hundreds of houses and also “surprised vendors and their clients in the markets”.

Innocent Mupenda, a civil society figure from the region, said a downpour started on Thursday afternoon, before the “river carried away villagers”.

His mother and 11 children died in the flood, Mupenda said.

Heavy downpours during rainy seasons in central Africa regularly lead to flooding and landslides.