The fight occurred barely two days after communities in Yenagoa placed a ban on cult activities in the area.
Three persons were killed on a road in the clash between the Dey-Well and Bobos groups, it was said.
Another person died in the Osiri area of Yenagoa suburbs.
Sources claimed it was not unconnected with political rivalry following the fallout of funds released to one of the groups by some unnamed politicians.
A popular entertainer, Laffcyrup Odumgele, on his Facebook page, called on the state government to take the issue of security seriously.
Police spokesman Asinim Butswat confirmed the incident, but said two persons were killed.
He added that the police arrested four persons in connection with incident, and that investigation was ongoing.