Gunmen shoot dead 18 in northwestern Nigeria over cattle

Police say gunmen have shot dead at least 18 people in Nigeria's northwestern Zamfara state.

State police spokesman Muhammad Shehu says an armed gang ambushed a group of residents in Birani village. He says the bandits were mobilized by cattle rustlers who had been prevented from stealing cows.

Some local media reports put the death toll as high as 40.

The incident is the latest in a series of killings by armed men who attack villages in northwestern Nigeria to steal cattle.

Amnesty International says thousands of people have been displaced and at least 168 killed since the beginning of this year as farmers and nomadic herdsmen fight over land in five Nigerian states.