At least 20 people died in a boat accident in southern Nigeria earlier this week, the country’s emergency agency and police said on Saturday.

Emergency workers have recovered 11 "burnt" bodies and are still searching for others, an official of the National Emergency Management Agency (NEMA) told AFP.

"The boat was a big ferry carrying over 100 people who are market merchants," said Adebiyi Babatunde Razaq from NEMA, noting that the accident occurred in the "early hours of Wednesday".

Nigeria's waterways authority said in a statement that the accident was caused by an "engine default explosion".

Although there has been no formal announcement about the cause of the accident, the state governor Duoye Diri has called for strict observation of safety regulations.

"The news is even more disturbing that the accident has claimed some lives and injured many hardworking and resilient traders who were out fending for themselves and their loved ones," Diri said in a statement on X.

Travel by boat is popular in Nigeria, especially in the coastal Niger Delta region.

The accident in the coastal southern Ijaw of Bayelsa State marks the latest boat tragedy in the country, where capsizes often occur due to overloading, poor safety and heavy flooding.

At least nine people, including five children, died after the boat in which they were travelling was hit by high waves in Andoni, in neighbouring Rivers state in January.

At least 24 farmers died after a boat capsized in north-central Nigeria last September.