The incident occurred on Thursday in Ogbolomabiri community, in the Nembe Local Government Area of Bayelsa State.
The clash was said to have caused pandemonium in the community as the suspected cult members looted shops and business premises operated by non-indigenes and indigenes.
It was learnt that Nengi, who was reportedly being chased by the members of the Nembe Youth Congress, jumped into a river and drowned.
It was said that when his corpse floated along the waterways, some "cult members" in his support went berserk and vented their anger on the buildings, cars and shops in the community.
They were said to have destroyed about 20 buildings, burnt vehicles and looted shops.
A house belonging to the father of a prominent chief in the community, Chief Nengi James, was reportedly torched by the rampaging youths.
A source from the community said, “Trouble started on Monday when a principal member of the Nembe Youth Congress slapped Isere around the venue of a chieftaincy installation.
“He was assaulted for leading a group of youths opposed to a traditional ruler who was recognised by the Amayanabo of Nembe, King Edmund Daukoru.”
The Nembe City Clan Chairman of the Ijaw Youth Council, Yenimi Dick-Agbe, who confirmed the incident, appealed to government to intervene in order to restore peace to the community.
But King Daukoru was said to have held an emergency meeting with members of his council of chiefs to stop the crisis.