The attackers stormed Abarikpo and Odiereke-Ubie communities in Rivers State on Wednesday morning, Grace Iringe-Koko, a local police spokesperson, told reporters in Port Harcourt, the state capital.
"Yes, I can confirm that six people were killed. An investigation is ongoing to apprehend the suspects," she said.
Security sources told Xinhua that the killings were suspected to be a reprisal attack linked to clashes with rival cultists in the area.
Armed attacks have been a primary security threat in some parts of Nigeria, leading to deaths and kidnappings in recent months.