GENEVA (AP) — The U.N.'s top human rights official says the Ebola outbreak and the Islamic State group represent "twin plagues" upon the world.

U.N. High Commissioner for Human Rights Zeid Raad al-Hussein says the two threats "both fomented quietly, neglected by a world" that misread their potential.

He told a news conference Thursday that his agency has begun drawing up guidelines for Ebola-hit nations to follow if they impose health quarantines on people, because such efforts can easily violate a wide range of human rights if imposed and enforced unjustly.

Zeid says the Islamic fighters who are seizing ground along the borders of Iraq and Syria represent "a diabolical, potentially genocidal movement" that is the product of "a perverse and lethal marriage of a new form of nihilism with the digital age."