People stranded due to floods following several days of downpours, in Kogi Nigeria October 6, 2022. [AP Photo]

The death toll from floods in Nigeria this year has increased to 603 as local authorities race to get relief items to hundreds of thousands being evacuated from their submerged homes.

More than 1.3 million people have been displaced by the disaster, which has affected people across 33 of Nigeria's 36 states, the nation's humanitarian affairs ministry said late Sunday.

At least 340,000 hectares of land also have been affected, worsening fears of food supply disruptions. Armed conflict already has threatened production in the northwest and central regions of Nigeria, which produce much of what the country eats.

Nigerian President Muhammadu Buhari directed "all concerned to work for the restoration of normalcy," according to a statement issued by the presidency.

Nigeria experiences annual flooding especially in coastal areas but this year's floods are the worst in more than a decade. Authorities blame the disaster this year on the release of excess water from Lagdo dam in neighboring Cameroon and on unusual rainfalls.

The flooding has worsened the humanitarian crisis in Nigeria where armed violence especially in the troubled northern region has already displaced more than 3 million people, according to the Internal Displacement Monitoring Center.

Sadiya Umar Farouq, Nigeria's minister of humanitarian affairs, warned that five states are still at risk of experiencing floods up till the end of November.

"We are calling on the respective state governments, local government councils and communities to prepare for more flooding by evacuating people living on flood plains to high grounds," Farouq said.

Last week, President Buhari approved 12,000 metric tons of grains for the flood victims, the humanitarian affairs minister said.