NIGERIA’S biggest city Lagos and several states were under curfews as unrest rooted in anti-police protests broke out again following a day of violence, including the shooting of civilians by security forces. Fires burned across Lagos and residents reported hearing gunfire despite President Muhammadu Buhari's appeal for "understanding and calm". Armed police tried to enforce a round-the-clock curfew in the commercial capital, setting up checkpoints. But groups of young men blocked a number of major roads with overturned traffic signs, tree branches and rocks. Smoke billowed from buildings that were ablaze. Video verified by Reuters showed armed police in the…