“The site has already suffered four years of conflict, it suffered from looting and represents an irreplaceable treasure for the Syrian people and for the world,” UNESCO Director-General Irina Bokova said.

She added, “I appeal to all parties to protect Palmyra and make every effort to prevent its destruction.”

According to several sources, armed extremist groups raided the city of Tadmur, home to the archaeological site of Palmyra. Inscribed on UNESCO’s World Heritage List, it is considered one of the most important cultural sites in the Middle East.

An oasis in the Syrian desert, northeast of Damascus, Palmyra contains the monumental ruins of a great city that was one of the most important cultural centres of the ancient world.