Sixteen people have been killed in two attacks in north-central Nigeria in a region struggling with intercommunal violence, the army said.

Clashes between nomadic herders and farming communities often flare in Plateau State, which sits on the dividing line between the mostly Muslim north and Nigeria's predominantly Christian south.

In the latest violence on Tuesday, half a dozen members of a local farmers self-defence group were killed by gunmen in Riyom district while another 10 people were killed in an attack in Mangu area, an army spokesman said.

"Six lives were lost in Riyom," said army Major Ishaku Takwa told AFP on Wednesday.

"Another attack took place in some communities in Mangu and 10 persons died."

Plateau state assembly member representing Mangu South, Bala Fwangje, said 14 people had been killed in that area.

"We heard that about 14 people were killed, houses destroyed, property burnt. I am yet to get the full details," he said.

Since May, nearly 200 people have been killed in clashes between the Berom farming communities, who are mainly Christian, and the cattle breeding communities of Fulani Muslims in the Riyom, Barkin Ladi and Mangu areas of Plateau.

It was unclear what exactly triggered the recent attacks in Plateau, but tit-for-tat killings between herders and farmers often spiral into village raids by heavily armed gangs who kidnap, loot and kill villagers.

The Plateau crisis is one of the many security challenges facing President Bola Tinubu who took the helm of Africa's most populous nation at the end of May.