The bones of a saint have been discovered among the ruins of an ancient monastery in the Christian town of al-Qaryatain, liberated from ISIS control on Sunday.

Photographs taken of the ruins of the Mar Elian (Saint Julian) monastry in al-Qaryatain appear to show a destroyed sarcophagus containing a skull and bones.

The town was liberated from Islamic State on Sunday, having been captured by the jihadist group in August last year.

The photographs, tweeted by Channel 4 News reporter Lindsey Hilsum, show bones laying on the ground amid rubble. There were also other bones stored in cardboard and plastic boxes.

The remains are thought to be of the namesake of the monastery, Saint Julian, who was martyred in 284 AD for refusing to deny his faith. The saint, who had healed the sick, was killed by his own father, a Roman officer.

He was buried in the sarcophagus, which had laid uncovered for centuries until ISIS used bulldozers to raze the Mar Elian monastery, which is more than 1,500 years old.

Syrian and allied forces backed by Russian air strikes forced Islamic State militants out of the Christian town on Sunday after encircling it over the past few days, Syria's military command said.

According to Russia Today, whose reporters have since visted the site, every Christian symbol within the monastery and church has been destroyed, and all the crosses removed. There is evidence that attempts to burn the building down were made, and Assyrian Christian holy books were also burnt. 

Surrounded by hills, al-Qaryatain is 100 km (60 miles) west of the ancient city of Palmyra, which government forces recaptured from Islamic State on 27 March.