The United Nations Educational, Scientific, and Cultural Organization(UNESCO) has added six ancient sites in Syria to the list of endangered World Heritage Sites.The sites include those in the ancient cities of Aleppo, Damascus, and Bosra. “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,” a UNESCO document said on Thursday. The oasis of Palmyra, the castle of Crac des Chevaliers and Qal-at Salah El-Din, also known as the Fortress of Salahin, and ancient villages located in northern Syria have also been listed as endangered sites. “The immediate, near-term and long-term effect of the crises on the cultural heritage of Aleppo cannot be overstated,” the document added. Since the unrest started in Syria in 2011, many people, including large numbers of Syrian soldiers and security personnel, have been killed in the violence. UNESCO has called for global cooperation in protecting the sites in Syria and other conflict zones, including Mali. The militants in Syria have already been accused of destroying parts of an ancient Umayyad mosque in Aleppo, back in April. There are growing concerns over the possible destruction of more sites in Syria with Takfiri militants taking position near the ancient citadels of Aleppo, Homs and Hama. Takfiris accuse most Islamic sects of being infidels.