Clashes in Nigeria between farmers and herders have killed more than 3,600 people since 2016, mostly this year, Amnesty International said Monday in a report documenting an escalation in violence that could affect the results of the February 2019 election.

President Mohammad Bukhari is seeking a second term in the election, but his campaign has been negatively affected by accusations of a lack of justice for one of the two sides responsible for the clashes, the shepherds, many of whom belong to the Buhari tribe of Fulani.

The presidency has repeatedly denied such accusations.

These acts of violence are often described as ethno-religious among herders, mostly Muslims from Fulani and mainly Christian farmers. But many experts and politicians say the climate has changed and the expansion of agriculture has created a land conflict that forces farmers and herders to clash regardless of religion or ethnicity.

"The failure of the Nigerian authorities to investigate sectarian clashes and prosecute the perpetrators has led to a dramatic escalation in the conflict between farmers and herders across the country, which has killed at least 3,641 people over the past three years and displaced thousands," Amnesty said in a statement. .

Nigeria's military and police have not responded to the request for comment.

Of the 310 attacks recorded between January 2016 and October 2018, 57 percent occurred in 2018, the WHO said.

The International Crisis Group said in July that the conflict between farmers and herders led to a death toll of six times more than those killed by the Boko Haram group in the first half of 2018.

"Because of the inaction of the security forces in some areas, competition for resources is used as a pretext for killing and maiming on ethnic or religious grounds," said Amnesty International Director Usay Ogujo.

"This conflict is also being seriously politicized by some state government officials who are fueling tensions through the process of blaming a party on a partisan basis," she said.