According to authorities, a boat carrying people down the River Niger in southwest Nigeria capsized, causing more than 100 people to drown and more to go missing.
More than 300 people were traveling on board the ship from Kwara state to Niger state following a wedding ceremony.
More victims may still be missing, officials said, so search and rescue operations are still ongoing.
According to a traditional local ruler, the boat sank after colliding with a tree.
In a statement released on Tuesday, Kwara state Governor AbdulRahman AbdulRazaq said that "dozens of people were feared killed and many others [are] still missing.".
More than 150 people had died, according to the Emir of Patigi, Ibrahim Umar Bologi II, the area's traditional ruler.
According to him, the boat capsized when river waves overtook it and forced it to crash into a tree that had washed into the river.
The death toll was probably going to increase as long as search and rescue operations went on, a Kwara state police spokesman told AFP.
Mr. AbdulRazaq, the governor of Kwara State, expressed his "heartfelt condolences" to the families of the victims and said rescuers were still looking for survivors.
River mishaps are frequent in this region of Nigeria.
The River Niger, which flows through the country's middle, is frequently used by residents of the villages that border it because it can be faster than the roads, which are frequently in poor condition and risky due to the presence of kidnapping gangs.
But in an effort to increase their profits, boat owners frequently overload their flimsy boats.