The United Nations cultural agency has called for an emergency meeting in the wake of a video published on Islamic State (Isis)-linked sites showing militants smashing ancient artefacts in a Mosul museum in Iraq.
"This attack is far more than a cultural tragedy - this is also a security issue as it fuels sectarianism, violent extremism and conflict in Iraq," UNESCO chief irina Bokova said in a statement.
The video shows men destroying the artefacts, some of them dating back to the 7th cenutry BC, with sledgehammers and drills. "These ruins that are behind me, they are idols and statues that people in the past used to worship instead of Allah," a bearded IS militant tells the camera.
"The Prophet Mohammed took down idols with his bare hands when he went into Mecca. We were ordered by our prophet to take down idols and destroy them, and the companions of the prophet did this after this time, when they conquered countries."
The militants are seen dragging the statues to the ground and using drills to destroy them, including a 3,000-old winged-bull Assyrian protective deity.
The systematic destruction of iconic components of Iraq's rich and diverse heritage that we have been witnessing over the past months is intolerable and it must stop immediately", Bokova said.
Mosul is in the centre of 1,791 registered archeological sites, including four capitals of the Assyrian empire - Nineveh, Kalhu, Sur Sharrukin and Ashur.
Fears is growing among the archeologists' community that jihadists would go on a rampage to destroy heritage sites in areas under their control in Iraq.
Two ancient sites - the UNESCO-heritage site Hatra and Nimrud - have been identified as being under danger of destruction. "This is not the end of the story and the international community must intervene," said Abdelamir Hamdani, an Iraqi archaeologist at New York's Stony Brook University, told AFP.
Hamdani, who worked in Iraq with the department of antiquities, reported that the jihadists told the museum guards that the would destroy Nimrud, one of the very important Assyrian capitals, and Hatra, an isolated site in the desert.
According to UNESCO Hatra's remains, mixing Hellenistic and Roman architecture with Eastern decorative features, "attest to the greatness of civilization".
Earlier, Mosul's public library director Ghanim al-Ta'an told The Fiscal Times that IS members burned the city public library, which housed more than 8,000 rare old books and manuscripts.
"IS militants bombed the Mosul Public Library. they used improvised explosive devices," he said.
A history professor at University of Mosul told AP that Islamists began destroying the library earlier this month. Another report said 2,000 books were seen being loaded into pickup tracks.