More than 200 people were killed in violence against farming communities last weekend in Plateau state, central Nigeria, according to a speech by the governor published on Wednesday.
Simon Lalong said after a closed-door meeting with President Muhammadu Buhari in the state capital Jos on Tuesday night that the clashes had left "the painful loss of over 200 people".
The police, who blame suspected cattle herders, have said 86 people were killed. However, multiple local sources from the communities affected maintained more than 100 people died.
The main association representing the largely nomadic herders has denied its community had any involvement in the killings and said its members had been repeatedly targeted for months.
The violence -- an apparent reprisal after ethnic Berom farmers allegedly killed five Fulani -- is the latest bout in months of bloodletting in Nigeria's so-called "Middle Belt".
The clashes are rooted in tensions over access to land between the pastoral herders and sedentary farmers but have generated sectarian friction between Muslims and Christians.
Lalong suggested "criminal elements" were exacerbating hostilities, including "conflict merchants" involved in "cattle rustling, theft, banditry, gun running" and other crimes.
Both he and Buhari have also warned about politicising the conflict or giving it a religious dimension.
- 'Terrorist invasion' -
Buhari came to power in 2015 on a promise to curb insecurity across the country, in particular Boko Haram, whose Islamist insurgency has killed at least 20,000 since 2009.
But a resurgence of violence in the long-running conflict between herders and farmers has put that under scrutiny as elections approach in February next year.
Analysts predict the extent of the unrest could eclipse that of the jihadists in the northeast.
Lalong said the latest attacks in Plateau were carried out with "sophisticated weapons" that were "reflective of a terrorist invasion".
"It (the bloodshed) therefore demands a justified response like that which was undertaken to address the Boko Haram insurgency," he added.
Lawmakers earlier this month threatened Buhari with impeachment because his security chiefs had repeatedly failed to protect lives and property.
The 75-year-old leader on Tuesday said he would "continue to pressurise members of the law enforcement agencies directly under me by the constitution as the commander-in-chief".
He also said it was an "injustice" to imply he was doing nothing because he was also Fulani and Muslim.
Police and army reinforcements have been sent to Plateau to improve security, while a dusk-to-dawn curfew remained in place in areas of the state affected by the violence.
- Resign call -
Plateau has been the scene of similar violence in the past but in the last three years has been relatively calm, as clashes have spread elsewhere.
Benue state in particular has become the epicentre of violence since the start of this year after it banned free grazing by cattle.
In April, herders were again blamed for an attack on a Roman Catholic church that killed two priests and 17 worshippers. In January, attacks on farming communities killed at least 80.
In a strongly-worded front page editorial on Wednesday, the financial daily Business Day questioned why the killings in Plateau and elsewhere had not been prevented.
"President Buhari has failed and continues to fail in his responsibility to protect Nigerians" as security chiefs had not been held to account for repeated attacks, the newspaper said.
He also appeared to have shown "high-level disinterest" in making security apparatus more effective to prevent violence, it added.
"If the President cannot handle the responsibility of protecting Nigerians he should do the honourable thing and resign from his position," it added.
"In a situation like this he should not even be seen talking about a second term."