By far, the greatest threat to Nineveh has been purposeful human actions by ISIL, which first occupied the area in the mid-2010s. In early 2015, they announced their intention to destroy the walls of Nineveh if the Iraqis tried to liberate the city. They also threatened to destroy artifacts. On February 26 they destroyed several items and statues in the Mosul Museum and are believed to have plundered others to sell overseas. The items were mostly from the Assyrian exhibit, which ISIL declared blasphemous and idolatrous. There were 300 items in the museum out of a total of 1,900, with the other 1,600 being taken to the National Museum of Iraq in Baghdad for security reasons prior to the 2014 Fall of Mosul. Some of the artifacts sold and/or destroyed were from Nineveh. Just a few days after the destruction of the museum pieces, they demolished remains at major UNESCO world heritage sites Khorsabad, Nimrud, and Hatra.