Operatives of OSPAC have been accused of killing a man in Igwuruta, Ikwerre Local Government Area of Rivers, and three others in Emohua Local Government.
In Igwuruta, the vigilante group was said to have killed the man following the accusation of belonging to a cult group and taking the body away.
The group which has, however, been disbanded in Emohua was, it was accused of killing three persons during a shootout in Ibaa Community on Saturday.
Chikwenekpe Emordu, whose brother, Chinedu Emordu was killed in the shooting said members of OSPAC carried out the attack.
He alleged that operatives of the vigilante group have engaged in senseless killings in the community, adding that it might plunge the community into further crises.
He, however, alleged that some politicians in the area are sponsoring the activities of the OSPAC operatives.
But Aleruchi Livingstone, secretary of the group in Ibaa community said the group has not been operating after being disbanded last month.
Livingstone said the killings in Ibaa were a result of a cult clash by a newly formed cult group The Bad Marlians, which he said has been terrorizing the community.