The chief of the U.N. education and culture organization UNESCO says the destruction and looting of archaeological sites in the Middle East must be condemned as a "war crime."

UNESCO Director-General Irina Bokova of Bulgaria also told a conference that opened in Egypt on Wednesday that the theft and destruction of antiquities in the region was a "tactic of war" designed to terrify populations, finance criminal activities and spread hatred.

The two-day conference is being held in response to the destruction of ancient temples and artifacts in Iraq by the extremist Islamic State group as well as the looting and smuggling of antiquities in Iraq, Syria, Egypt and Libya.

A total of 10 Arab nations are represented in the conference.