Paris, May 21 (IANS): Following reports that the Islamic State militants have infiltrated the Palmyra world heritage site, where fight is going on, the Unesco on Thursday called for an immediate end to hostilities in Syria's ancient city.

"I am deeply concerned by the situation at the site of Palmyra. The fight is putting at risk one of the most significant sites in the Middle-East, and its civilian population," said Unesco director-general Irina Bokova in a statement.

"I call on the international community to do everything in its power to protect the affected civilian population and safeguard the unique cultural heritage of Palmyra," she added.

Bokova also said that all parties should respect international obligations to protect cultural heritage during conflict, by avoiding direct targeting, as well as use for military purposes.

Palmyra, an oasis in the Syrian desert, was a leading cultural centre in the first and second centuries A.D. and later became an important stop for Silk Road caravans.

Prior to the start of Syria's civil war in March 2011, the Palmyra ruins were one of the country's foremost tourist attractions.