ABUJA, NIGERIA - Officials in Nigeria say the death toll from an attack on animal herders has risen to 40. The strike took place Wednesday in Rukubi, a village on the border between Nigeria's Nassarawa and Benue states, a region known for ethnic and religious conflict.

Nassarawa state governor Abdullahi Sule has refuted claims that a military jet bombed pastoralists and said Thursday it was an unidentified drone operated from an unknown location that exploded.

He said he has deployed security operatives to the area to prevent tensions or reprisals.

'I've been on it all night trying to resolve the matter with chief of defense staff, Miyetti Allah, and all the security agencies including our commissioner of police to ensure that we continue to douse the tension that may generate as a result of this,' Sule said.

Pastoralists were returning from nearby Benue state with hundreds of cattle they had bailed out from officials enforcing an anti-open grazing law when the bomb exploded among them.

Sule said 40 people were killed and many others were injured. Many herds were also affected.

A Nigerian Air Force spokesperson did not take calls from VOA for comment. However, Nassarawa state police spokesman Nansel Ramham told VOA by phone that authorities are investigating.

Farmers and herders in central Nigeria have been clashing over grazing land for decades. Benue and Nassarawa are the most affected.

An umbrella group for cattle breeders in Nigeria, the Miyetti Allah Cattle Breeders Association of Nigeria, condemned the attack Thursday and asked authorities to capture the perpetrators.

Abuja-based Beacon Security analyst Kabiru Adamu said the attacks could be the result of wrong profiling.

'Nobody as at date, not the military, not the state governor, Miyetti Allah Cattle Breeders Association, has been able to clarify what type of incendiary attack it was. The media has created this monster called Fulani herdsmen. It's been highlighted by the media to the extend that stigmatization and profiling has occurred,' Adamu said.

But the Nigerian military has in the past recorded accidental airstrikes on civilians while battling Islamist militants and armed gangs in the northern region.

In January 2017, more than 100 people were killed when a military jet hit a camp housing people displaced by jihadist violence in the town of Rann, in northeast Borno state.

The military blamed the attack on a lack of appropriate markings of the area.

Last year, an arms trade between the United States and the Nigerian government was stalled due to concerns about extrajudicial killings.

Adamu said authorities should be more proactive.

'By now I expect that the National Assembly would have set up a committee to look at this latest incident in Doma, identify what went wrong and introduce measures to prevent a reoccurrence,' Adamu said. 'It could have been mistaken identity or poor intelligence that may have suggested the movement was by bandits.'

Security is a significant challenge and a major issue as Nigeria prepares for presidential and parliamentary polls next month.