At least 76 people were killed after a boat capsized in the southern state of Anambra, President Muhammadu Buhari confirmed in a statement.
In the statement issued late Sunday, Buhari acknowledged that rescue agencies had officially reported the death toll of the tragedy on October 7, reports Xinhua news agency.
The passenger boat carrying 85 people capsized in the state's Ogbaru area, following rising floods in that area, according to the statement.
An investigation had been launched to determine "other causes of the incident" besides floods, Thickman Tanimu, an official from the National Emergency Management Agency (NEMA) was quoted as saying by local media.
Following the tragedy, Nigeria's National Inland Waterways Authority and the NEMA have embarked on rescue and recovery missions in Anambra.
The President has also ordered a review of safety measures across the country's water transport system and said emergency services must do everything to account for those missing.
Buhari called on government agencies "to check the safety protocols on these transport ferries to make sure such incidents are avoided in the future".