At least 86 people died after violent clashes broke out between farmers and cattle herders in Nigeria’s Plateau state on Saturday, local news website Premium Times reported. The violence was reportedly sparked by an attack by ethnic Berom farmers on Fulani herders on Thursday.

The violence led to reprisal attacks in the state capital of Jos on Sunday, forcing the government to declare a curfew from 6 pm on Sunday (10.30 pm Indian time) to 6 am on Monday (10.30 am Indian time). Police spokesperson Terna Tyopev, in a statement, confirmed that six people were injured in the clashes and 50 houses were destroyed.

Commander of the Special Military Task Force, Major General Anthony Atolagbe, told Lagos-based Vanguard that they had arrested three people for being involved in the clashes. “The suspected killers have been giving useful information about others involved in the killings and their hideouts,” he said. “We are going all out for them. Also, troops have been deployed to ensure normalcy is restored.”

On Sunday, ethnic Berom youths set up barricades on the highway leading to Nigerian capital Abuja and attacked motorists who “looked Fulani and Muslim”, AFP reported. Several vehicles were vandalised.

Nigeria’s President Muhammadu Buhari appealed for calm as the military and police tried to end the clashes. He said “no efforts will be spared” to find the attackers and prevent reprisal attacks.

Deadly clashes between herders and farmers in central Nigeria are a growing security concern in Nigeria, which is roughly split between Muslims in the north and Christians in the south, reported Time. Settled farming communities and nomadic cattle herders often clash – usually over access to land and grazing rights. Farmers are mostly Christian, while herders are ethnic Fulani and mostly Muslim.