The U.N. human rights chief is warning that an explosion of violence is close in Burundi, sparked by the president's decision to seek a third term and a crackdown especially by the youth wing of his ruling party, which has carried out dozens of recent killings.

Zeid Raad al-Hussein told the U.N. Security Council on Thursday that "the risk to human life, and to regional stability and development, is high" as a result of escalating politically motivated violence and the impoverished nation's history of recurring bloodshed.

He says his office has documented dozens of killings in the past two months, most of them shootings of demonstrators and human rights defenders by the youth wing and security forces.

He urges Burundi's government to disarm the Imbonerakure youth wing immediately.