Nigeria is to conduct a review into animal grazing rights following deadly clashes between herders and farmers who complain about livestock destroying their crops.

The review will examine grazing sites in 25 states.

A statement by President Muhammadu Buhari's spokesman, Garba Shehu, said the review will determine the level of encroachment on the grazing sites.

He explained that the number of the grazing reserves and states were reached at after considering security concerns and other socio-economic conditions.

Previous government proposals were criticised for favouring the herders, who are mainly from President Buhari's tribe.

Many southern Nigerian states have called for open grazing to be banned, arguing that cattle breeders should set up ranches for their animals.