The death toll from a boat accident in Nigeria's southeastern state of Anambra has risen to 76, the president said on Sunday.

The vessel capsized on Friday amid heavy flooding in the Ogbaru area of Anambra, according to officials on Saturday, when they said at least 10 people had died and 60 were missing.

In a statement posted on Twitter on Sunday, Nigeria's President Muhammadu Buhari said that emergency authorities had confirmed the higher death toll.

Authorities are working to rescue or recover any missing passengers, said Buhari, adding that he had directed the relevant agencies to check safety protocols to prevent future accidents.

The head of Anambra State Emergency Management Agency said that 15 people had been rescued as of Saturday night.

Anambra is among 29 of Nigeria's 36 states to have experienced heavy flooding this year. The waters have washed away homes, crops and roads and affected at least half a million people.

A local resident, Afam Ogene, told Reuters that because flooding had destroyed the major road linking eight communities to the rest of the area, some residents had to travel by boat.

Of the vessel that capsized, he said it was locally made and had the capacity to carry more than 100 people. He added that the boat's engine had failed and it was overpowered by waves shortly after it launched.