The world must act to save Palmyra, Syria's antiquities chief said Thursday, accusing the international community of standing by as the Islamic State jihadist group seized the ancient city.

Mamoun Abdulkarim described the capture of the world heritage site by IS as "a loss for all of humanity, for world civilisation in the face of barbarism".

"I call on the international community to stop standing with arms crossed. The world must mobilise to prevent the (looting and) smuggling and destruction of this precious Syrian heritage," he added.

"It is a global battle," Abdulkarim told AFP in Damascus.

Palmyra is known worldwide for its Greco-Roman ruins and ornate tombs, now at risk of destruction by the extremist group.

Abdulkarim said antiquities officials had done all they could to transfer hundreds of statues and priceless artefacts out of Palmyra.

"But we are still afraid for the large ruins, like the tombs and temples."

"If the jihadists are kicked out by force, the city would become a battlefield -- and if they stay, these barbarians would destroy the ruins," Abdulkarim added.

"We will never forget Palmyra," he said, saying it was taken "hostage" by IS.