More than 600 people have died and 1.3mn have been displaced from their homes in flooding that has hit 33 of Nigeria’s 36 states and the capital Abuja, government officials have said.

The government said an unusually heavy rainy season aggravated by climate change and the discharge of excess water from a dam caused the severe flooding, adding that some states and local governments did not heed warnings to make bigger preparations to assist people in the worst affected areas.

Sadiya Umar Farouq, the humanitarian affairs and disaster management minister, said more than 108,000 hectares of farmland have been submerged, and critical infrastructure such as roads have been destroyed. More than 200,000 homes have also been partially or completely destroyed. Several rice producing states in northern and central Nigeria are among the worst affected, raising concerns about shortages at a time when annual food inflation has hit 23 percent.

A boat carrying at least 80 people fleeing rising water levels capsized in the south-eastern state of Anambra earlier this month, killing at least 76.

Farouq warned that the southern states of Anambra, Delta, Cross River, Rivers and Bayelsa could suffer more flooding into November and urged state and local governments to prepare to evacuate “people living on flood plains to high grounds, providing tents and relief materials, freshwater as well as medical supplies for possible outbreaks of waterborne diseases”.

President Muhammadu Buhari has ordered the release of 12,000 tonnes of foodstuffs from the nation’s strategic reserves.

Farouq appeared to blame state and local administrations for a lack of preparedness. “There was enough warning and information about the 2022 flood but states, local governments and communities appeared not to take heed,” she said.

The floods were exacerbated by the release of excess water from the Lagdo dam in neighboring Cameroon. Nigeria’s National Emergency Management

Agency warned last month that water would “cascade down to Nigeria through River Benue and its tributaries, thereby inundating communities that have already been impacted by heavy precipitation”.

Nigeria’s inland water reservoirs are also expected to continue overflowing until the end of October.