3.4 million people have been displaced by flooding in west and central Africa

The UN's refugee agency said Friday that destruction from flooding has displaced more than 3.4 million people in west and central Africa.

UNHCR said Friday that Nigeria's worst floods in a decade have killed hundreds, displaced 1.3 million residents and affected over 2.8 million people in the West African nation of 218 million.

Survivors had to scurry for higher ground as water submerged farmland and infrastructure. Many have been living in camps for the internally displaced that were set up in part to help people fleeing simmering violence in the region, among other troubles.

"The climate crisis is happening now — destroying livelihoods, disrupting food security, aggravating conflicts over scarce resources and driving displacement," UNHCR spokesperson Olga Sarrado said.

"The link between climate shocks and displacement is clear and growing."

The agency noted that the government in Chad, where floodwaters affected more than a million people, has declared a state of emergency.

Floods also have killed hundreds of people and displaced thousands in Niger, Mali and Burkina Faso, UNHCR said.

The downpours in West Africa contrast with the worst drought in 40 years in the Horn of Africa.

Nigeria records flooding every year, often as a result of inadequate infrastructure and non-adherence to environmental guidelines.

Authorities in September blamed this year's floods on water overflowing from some local rivers, unusual rainfalls and the release of excess water from Lagdo dam in the northern region of neighbouring Cameroon.