Nigeria’s President Muhammadu Buhari has warned that those responsible for the communal violence in the northern Plateau state will not be spared.
Police said at least 86 people died in clashes between farmers and nomadic herders but unofficial figures put the number at more than 100.
A curfew has been imposed in affected areas to prevent further violence.
The clashes began on Thursday when a group of herders was attacked, prompting retaliatory killings on Saturday.
Police said 50 houses had also been burnt down.
A BBC correspondent in Lagos says the region is prone to religious tension – herders are mostly Muslim, while the farmers are mainly Christian.