"The 46 casualties were from the bodies of victims found and retrieved. Many people are still missing, so the number of those killed may be higher," Paul Hemba, security adviser to Benue State governor, told AFP.
The attack happened on Wednesday in Umogidi community, Benue State, where tit-for-tat clashes are common between nomadic herders and settled farmers competing for land and resources.
Hemba said "Soldiers have been dispatched to the area, so the situation is a bit calm now."
Authorities said the motive for the attack is not clear presently.
But Baba Usman Ngelzarma, chairman of the Myetti Allah Cattle Breeders Association of Nigeria (MACBAN), a union of Fulani herders, warned against blaming herders without investigation.
"There is a deliberate campaign of demonization of Fulani herders which started in Benue and spread to other parts of Nigeria," he said.
"We are not exonerating Fulani herders from involvement in some of the attacks but the way they are always blamed for every attack is unfair and prejudiced."
He called for an investigation to find the real perpetrators.
Intercommunal violence has spiraled into broader criminality in the northwest and center of the country, where heavily armed bandit militias ransack villages and carry out mass abductions for ransom.
Communal violence is just one of the security challenges facing President-elect Bola Tinubu who won a February presidential ballot that was marked by heavy delays and accusations of vote rigging.
Security forces are also battling a 14-year-long jihadist conflict and attacks by separatists.