The discovery in the Barikin Ladi area of Plateau state came after days of violence apparently sparked by an attack by ethnic Berom farmers on Fulani herders on Thursday, AFP reported on Monday.
State police commissioner Undie Adie said a search of Berom villages in the area following clashes on Saturday found "86 persons altogether were killed".
Adie told reporters six people were also injured and 50 houses razed. Bodies of those who died have been released to their families, he added.
The deaths are the latest in a long-running battle for land and resources that is putting President Muhammadu Buhari under pressure as elections approach next year.
The violence – fueled by ethnic, religious and political allegiances – has killed thousands over several decades.
Analysts believe it could become Nigeria's biggest security concern, eclipsing Boko Haram's insurgency that has left at least 20,000 dead since 2009.
The Plateau state government said it had imposed restrictions on movements in the Riyom, Barikin Ladi and Jos South areas "to avert a breakdown of law and order".
On Sunday, ethnic Berom youths set up barricades on the Jos-Abuja highway and attacked motorists who looked "Fulani and Muslim", according to those who escaped the violence.
Plateau state police spokesman Tyopev Terna and Major Adam Umar, from the military taskforce in the state capital, Jos, confirmed the blockade and vandalism to several cars.
There were no official reports of deaths but Baba Bala, who escaped the violence on the road, said at least six people were killed.
"I escaped with a smashed windscreen and dents on my car. I saw six dead bodies and several damaged cars," he added.
Plateau state governor Simon Lalong called for calm.
"Operational plans are currently being put in place to secure the affected communities and fish out perpetrators of these crimes," he said.
"While we pray for God's guidance through this difficult time, we will do everything humanly possible to secure our state immediately."
But the violence in Plateau followed a pattern that has become familiar in the state and elsewhere and which the authorities appear unable to stop.
On Thursday, Berom farmers attacked five ethnic Fulani herders travelling with their cattle in a truck at Heipang, in Barikin Ladi.
Police spokesman Terna said: "We recorded a crime in Heipang which I can describe as arson and kidnapping.
"We are searching for the five victims because we have not seen any corpses."
On Friday, two Berom children were killed in Arangai and Mangu Halle villages in what appeared to be reprisal attacks.
Terna said there were more reprisals on Berom villages in the Gashish area of Barikin Ladi which were "believed to have been carried out by Fulani herdsmen". "This led to today's violence," he added.