Suspected ethnic Fulani herders killed at least 15 villagers and burnt down homes in Taraba state in a dispute over grazing rights, police said on Wednesday.
State police spokesman Kwaji Joseph told AFP the incident happened on Sunday when the herdsmen stormed Dori and Mesuma in the Gashaka local government area.
"A group of people numbering about 20, suspected to be Fulani herdsmen, invaded and attacked Dori and Mesuma villages via Garbabi ward and burnt some thatched houses, forcing the villagers to flee into the villages of Mayo-Selbe and Sabon Gida for safety," he added.
"Eight people were killed in Dori while seven were also killed in Mesuma."
Police have been drafted to the area to contain the violence and "normalcy has since returned to the two villages", Joseph said, adding two people have been arrested.
Local media put the death toll higher, saying 44 people were killed and dozens of houses razed in the clashes.
The attack is the latest in a long-running dispute over grazing rights in Nigeria.
In the nearby central states of Benue and Plateau, deadly ethnic clashes are common. Recent violence in Benue is said to have killed hundreds of the ethnic Agatu community.
The largely agrarian Christian communities maintain the Muslim Fulani herdsmen are engaged in a prolonged battle to gobble up land from the areas of so-called indigenous people.
Fulani leaders counter their people face discrimination and are deprived of basic rights, including access to land, education and political office, despite having lived in the area for generations.