At least 321 people have been killed and over 740,000 others displaced in Nigeria so far this year due to the floods that ravaged most parts of the country, authorities said on Thursday.

In addition, some 2,854 people have been injured in the flooding, caused mainly by prolonged rainfall across the most populous African country, Chukwuma Soludo, governor of the southeastern state of Anambra, told reporters in the capital of Abuja, after a monthly National Economic Council meeting presided over by Vice President Kashim Shettima.

"The country is facing a national emergency concerning flooding and the reports so far identify a major national disaster," as the rains have led to widespread displacement, loss of lives, and destruction of homes and livelihoods, Soludo said, citing briefings at the Economic Council meeting.

The senior official said that 34 out of Nigeria's 36 states have experienced flooding, and 217 out of the 774 local government areas in the country have been affected. The ravaging floods have displaced at least 740,743 people, and destroyed or affected 281,000 houses and 258,000 cultivated farmlands.

In response to the national disaster, the Economic Council, which statutorily comprises of the vice president and all 36 state governors, has directed a comprehensive integrity review of the state of local waterways and dams to mitigate the ravaging impact of flooding.

"There was a serious emphasis on the need for a massive program of dredging of the waterways. The council also urged governors who have not submitted their reports on the flooding situation and management in their states to do so immediately," Soludo added.