World Bulletin / News Desk 

ISIL is in complete control of the Syrian city of Palmyra, including the military airport and prison, after the "collapse" of pro-government forces there, the armed group said on Thursday in a statement on Twitter.

The retreating forces "left behind a large number of (their) dead" which it said filled the city square, the statement said.

Clashes took place after ISIL took control of the town of al-Sokhna located 70 kilometers east of Tadmur.

Khaled al-Homsi, a member of Tadmur’s media coordination team, told that ISIL seized the government’s local directorate, which includes the state security’s building in the northern part of the city.

“Regime forces were seen carrying a number of monumental artifacts while withdrawing from a security point in the southern part of the city,” Khaled said.

Palmyra is also a strategic military gain, home to modern army installations and situated on a desert highway linking the capital Damascus with Syria's eastern provinces, mostly under insurgent control.

The Syrian Observatory for Human Rights monitoring group said ISIL had seized almost all of the city. It said it was unclear what had happened to forces stationed at an army outpost on its outskirts or the fate of a major military prison.

Syria's antiquities chief Maamoun Abdulkarim told earlier on Wednesday that hundreds of statues had been moved to safe locations but called on the Syrian army, opposition and international community to save the site.

"The fear is for the museum and the large monuments that cannot be moved," he said, "This is the entire world's battle."

In Washington, State Department spokeswoman Marie Harf expressed deep concern at the prospect that ISIL could seize the site.

"We hope that these sites are not further damaged by the fighting", she told reporters noting that they have already been harmed in fighting between Syrian government and opposition forces.