Pulaku: The two faces of Nigeria’s vigilantes

On a Tuesday afternoon in late September, three Toyota Hilux trucks make their way out of Yola and into the open savanna of northeastern Nigeria.

Inside, about 30 men wear the same olive-green uniforms. Some wear combat boots; others wear rubber shoes. They carry an assortment of weapons: Locally made firearms, machetes, and long wooden sticks more commonly associated wi...