UNESCO has added six ancient Syrian sites to the endangered World Heritage list.
UNESCO (the United Nations Educational, Scientific and Cultural Organisation) warned that more than two years of civil war had inflicted heavy damage on the sites, including the ancient cities of Damascus, Bosra and Aleppo, the oasis ruins of Palmyra and Crac des Chevaliers, one of the best preserved medieval castles in the world.
The ancient villages of northern Syria are also listed.
A statement on the UNESCO website read:
"Due to the armed conflict situation in Syria, the conditions are no longer present to ensure the conservation and protection of the outstanding universal value of the six World Heritage properties."
UNESCO announced the additions to its list of endangered sites at its annual meeting in the Cambodian capital Phnom Penh.
Preparatory documents seen by AFP said that UNESCO based its information on unverified sources, including social media and a report from Syrian authorities.
However, the UN cultural watchdog gave the main cause for raising the alarm as being that the sites were "of outstanding universal value for humanity as a whole," and therefore in need of protection.
There have already been instances of irreparable destruction caused by the conflict in Syria.
In April, the minaret of Aleppo's ancient Umayyad mosque — built in the 8th century and rebuilt in the 13th century — was flattened.
Aleppo's old city had "witnessed some of the conflict's most brutal destruction," UNESCO said, with the old citadel most at risk in the crossfire.