Sectarian clashes in volatile central Nigeria have left 23 people dead in the last week, in a region where bitter ethnic disputes have killed thousands in recent years, the military told AFP Wednesday.

Details of the 20 and 21 March attacks were slow to emerge from Plateau state, which falls on the dividing line between Nigeria's mostly Christian south and predominately Muslim north.

Military spokesman Lieutenant Jude Akpa said that 11 members of the mainly Muslim Fulani ethnic group, known largely as nomadic herders, were killed on 20 March after crossing onto land belonging to members of a Christian tribe called the Ataka.

The next day, Fulani gunmen reportedly returned to the same area of Riyom district and carried out what Akpa termed "a reprisal" attack.

"On the 20th, the 11 people killed were Fulani...and on the 21st the 12 were known as Ataka," he said.

Feuds over land and political rights have killed about 4,000 people in Plateau since 2001, the International Crisis Group said in a report last year.

The area's Christian ethnic groups consider themselves indigenes and accuse Muslim herders from the north of trying to appropriate wide swatches of land.

The state has consistently been led by Christian politicians, with Fulani groups claiming they have been denied basic rights, including the ability to formally own land.

Nigeria's constitution grants enhanced rights to those designated indigenes, giving Plateau's Christians better access to public education and public sector employment.

Nigeria's so-called "Middle Belt" was once pointed to as an example of peaceful co-existence among religiously divided communities but its reputation has changed amid sporadic periods of intense violence over the last decade.

A number of peace initiatives have been launched to pacify the state, but the violence has persisted.

A recent flare up occurred in July when a weekend of unrest blamed on Fulani gunmen left an estimated 100 people dead.

Extremist Islamist group Boko Haram, which has waged a deadly insurgency in north and central Nigeria that has killed hundreds since 2009, has also been blamed for past violence in the state.