"Some 23 corpses have been recovered following the fighting between Ologba and Egba communities in Agatu local government area of the state," state police spokesman Austin Ezeani told AFP.
He said several villagers were also injured, adding that the latest clashes in the region centred on a dispute over fishing rights in the area.
"The two neighbours were fighting over ownership of a fish pond. The violence broke out on Friday and continued until Saturday with many people also injured," he said.
"The Egba people believed the Fulani herdsmen could not have entered their community without passing through Ologba. So they believed the Ologba villagers must have aided the Fulani in that attack," he said.
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He said police had deployed to the area. "We have contained the violence. The place is now calm."
Local media said between 45 and 60 people were killed in the clashes.
Hundreds of people have been killed in attacks and reprisal attacks between farmers and ethnic Fulani herdsmen in the past few years in the state.
Benue state falls in Nigeria's so-called "Middle Belt", where the mainly Christian south meets the majority Muslim north, and has been the site of waves of sectarian and communal violence in recent years.
A six-year-old Boko Haram insurgency in Nigeria's northeast has claimed 13,000 lives and sent about 1.5 million people fleeing their homes.
The Islamists have in recent months widened their attacks into neighbouring nations, prompting Chad, Cameroon and Niger to launch a joint offensive with the Nigerian army, resulting in a series of rebel-held towns and villages being recaptured in Nigeria's northeast.