Top United Nations officials on Wednesday issued a joint statement urging an immediate end to the destruction of cultural heritage in war-torn Syria.

The joint statement was made by UN Secretary-General Ban Ki- moon, Director-General of the UN Educational, Scientific and Cultural Organization (UNESCO) Irina Bokova and UN-League of Arab States Joint Special Representative for Syria Lakhdar Brahimi, as the ongoing Syrian crisis enters its fourth year.

"As the people of Syria continue to endure incalculable human suffering and loss, their country's rich tapestry of cultural heritage is being ripped to shreds," said the joint statement.

World Heritage sites have suffered "considerable" and sometimes "irreversible" damage, the statement said.

Four sites are being used for military purposes or have been transformed into battlefields: Palmyra, an ancient Arabic city in central Syria; Crac des Chevaliers, Syria's best preserved castle from the Crusader of the Middle Ages; the Saint Simeon Church in the Ancient villages of Northern Syria; Aleppo, including the Aleppo Citadel.

"Archaeological sites are being systematically looted and the illicit trafficking of cultural objects has reached unprecedented levels," the statement said, adding that human representations in art are being destroyed by extremist groups intent on eradicating unique testimonies of Syria's rich cultural diversity.

"All layers of Syrian culture are now under attack -- including pre-Christian, Christian and Muslim," said the statement.

In the joint statement, the three UN senior officials said that the destruction of such precious heritage gravely affects the identity and history of the Syrian people and all humanity, damaging the foundations of society for many years to come.

They stressed that "the protection of cultural heritage, both tangible and intangible, is inseparable from the protection of human lives, and should be an integral part of humanitarian and peace-building efforts."

Therefore, the three called on all parties to halt immediately all destruction of Syrian heritage, and to save Syria's rich social mosaic and cultural heritage by protecting its World Heritage Sites in line with UN Security Council resolutions.

"We condemn the use of cultural sites for military purposes and call on all parties to the conflict to uphold international obligations, notably the 1954 Hague Convention for the protection of cultural property in the event of Armed Conflict and customary international humanitarian law," they said.

They also appealed to all countries and professional bodies involved in customs, trade and the art market, as well as individuals and tourists, to stay alert for stolen Syrian artifacts, to verify the origin of cultural property that might be illegally imported, exported and/or offered for sale, and to adhere to the UNESCO 1970 Convention on illicit trafficking of cultural property.

Meanwhile, the three UN officials underlined that the efforts to save Syria's cultural heritage must be part of wider efforts to end violence and move to peace.

"Destroying the inheritance of the past robs future generations of a powerful legacy, deepens hatred and despair and undermines all attempts to foster reconciliation," they noted.

"Now is the time to stop the destruction, build peace and protect our common heritage," they added.