The destruction of the ancient Assyrian city of Nimrud by ISIS extremist in Iraq constitutes a war crime, the UN's cultural body UNESCO said Friday. According to dpa, Iraqi officials said the militants began on Thursday to destroy the site, which covers an area spanning about 8 kilometres and contains numerous treasures, including royal tombs. "The deliberate destruction of cultural heritage is a war crime," said a statement from UNESCO chief Irina Bokova. She said there is "no political or religious justification for the destruction of humanity's cultural heritage."