A series of heavy rain and strong winds hit the northeastern Nigerian city of Benin, where at least 20 people have been killed, according to the UN.
The heavy rains have prompted fears that more flooding is possible as a result of the floods, which have been blamed on the spread of the Zika virus.
The WHO said that an estimated 6,000 people were affected by the floods in the city of Ndola.
The city has been hit by flooding for two weeks, with some areas flooding in one day, the United Nations’ emergency relief coordinator, Robert Booth, said in a statement.
He said that the city had suffered a record number of landslides.
The World Health Organization has confirmed the outbreak of the virus in the northeast region of Nigeria, with nearly 7,000 cases and 4,500 deaths reported.
Booth added that the virus has also been found in Guinea, Liberia, Nigeria and Senegal.
The UN has urged all governments and international organizations to mobilize immediately and deploy aid to the region.
“The region is in an extraordinary situation and we are deeply concerned about the ongoing situation in Benina, where more than 200 people have died from waterlogged homes,” Booth said.
Meanwhile, officials in Guinea have ordered the evacuation of about 30,000 residents from the city because of its proximity to the Zika outbreak, according the Associated Press.