Police in Jamaica have killed a top gang leader whose death has unleashed a violent backlash near the capital of Kingston as authorities were placed under an extreme threat level.

Roland Ball is facing first-degree murder charges in what police consider a gang retaliation ambush shooting that killed 17-year-old Inandi Wyche.

Prince, leading to a complete breakdown of government authority without additional international support for the beleaguered national police, the United Nations chief warned.