- The paramount ruler of the Tiv tribe, James Ayatse, urged Buhari to act to prevent a repeat, with impunity for those responsible seen as fuelling the violence.
- Police have also sent reinforcements into the affected areas while in Benue, civilian militia groups have been set up.
Huge crowds turned out in central Nigeria on Thursday at a funeral service for scores of people killed during clashes between cattle herders and farming communities.
Tens of thousands of people, many of them dressed in black, gathered in Ibrahim Babangida Square in the Benue state capital, Makurdi, for the ceremony before a mass burial on the outskirts of the city.
Emergency officials told AFP on Tuesday that 80 people had been killed and some 80,000 forced from their homes since the start of the year, in violence that has seen mounting calls for President Muhammadu Buhari to act.
Benue state governor Samuel Ortom said 73 of the victims, who included pregnant women, children and the elderly, would be buried on Thursday.
He told mourners there was "no doubt as to the motive of the wanton killing of our people and (the) destruction of our farms, property and our crops".
"This is all about land," he said.
The crowds began wailing as the simple, polished darkwood caskets were brought to the square on flat-bed trucks, according to an AFP reporter at the scene.
Violence between the mainly Muslim Fulani herdsmen and Christian farmers has claimed thousands of lives across Nigeria's central states over the past few decades.
The conflict is being driven by an increasing need for resources -- primarily land and water -- and is often exacerbated by ethnic and sectarian grievances.
But the scale of the recent killings, and similar tit-for-tat attacks in the neighbouring state of Taraba last weekend, has put Buhari's government and its response under the scanner.
The presidency said on Wednesday that the Nigerian Army had deployed special forces to Benue, Taraba and Nasarawa "to secure vulnerable communities and prevent further attacks".
Police have also sent reinforcements into the affected areas while in Benue, civilian militia groups have been set up.
The attacks in Benue against ethnic Tiv farmers have been seen as a response by the mainly nomadic herders to the introduction of a law banning open grazing in the state.
But Ortom refused to back down.
"If these killings by our enemies are to deter us from operating the anti-open grazing law in Benue state that was legally accessed, they have failed," he said.
Buhari -- himself a Hausa-speaking Fulani -- has been criticised for failing to take stronger action against his kinsmen but has rejected being soft on the issue.
His government has proposed the creation of cattle colonies across the country to provide grass and water for herds, plus education and healthcare for herders.
So-called "agro-rangers" will provide security, it added.
With tensions running high, the issue is taking on greater political significance as elections approach in February next year at which Buhari is expected to stand.
Banners seen in the crowd in Makurdi on Thursday included direct appeals to the head of state.
One read: "Ranching is the only option to end Benue killing." Another said: "Mr President, wake up."
The presidency said eight suspected Fulani herdsmen were in custody and being questioned in connection with the attack.
The paramount ruler of the Tiv tribe, James Ayatse, urged Buhari to act to prevent a repeat, with impunity for those responsible seen as fuelling the violence.
The perceived failure of Buhari's predecessor, Goodluck Jonathan, to act against Boko Haram jihadists in northeast Nigeria was seen as a key factor in his election defeat in 2015.
Nigerian writer and Nobel laureate Wole Soyinka said Buhari, his government and the police appeared to be "in near-identical denial" about the herders' threat to security.
"The ghosts of Jonathan seem poised to haunt the tenure of Muhammadu Buhari," he said in comments reported by Nigerian newspapers on Thursday.