LAGOS: Police in Nigeria have found at least 15 unidentified corpses floating on a river in southeast Anambra state, officials said Sunday, while local media said the number of bodies could be much higher.

"I don't know the exact number of bodies but I have seen at least 15 corpses floating on the river," Anambra police commissioner Bala Nasarawa said in a television interview after visiting the scene.

Some local media reports put the number of corpses at between 30 and 40.

It was unclear how the people had died or how their bodies ended up in the river. Nasarawa said police were investigating the mysterious case.

Television showed footage of what appeared to be male corpses in the Ezu river in Amansea, a border community between Anambra and neighbouring Enugu state.

The Enugu police commissioner, Musa Daura, who also visited the scene, said there had been no recent reports of communal clashes in the area.

Local reports said the corpses were first discovered Saturday by fishermen and sand excavators, who alerted authorities.