Ancient Palmyra
Ancient PalmyraReuters

Syrian regime forces strengthened their hold on Palmyra on Monday and pushed forward against the Islamic State (ISIS) jihadist group after dealing it a major blow by retaking the ancient city.

Antiquities director Maamoun Abdulkarim said that with UNESCO's approval the treasured monuments damaged or destroyed by the jihadists could be restored in five years.

Government troops and allied militia, backed by Russian air and ground support, overran Palmyra on Sunday morning after nearly 10 months of ISIS rule.

President Bashar al-Assad hailed the victory as "fresh proof of the efficiency of the Syrian army and its allies in fighting terrorism."

Regime forces turned to nearby ISIS-held towns on Monday, including Al-Qaryatain, southwest of Palmyra, and Sukhnah towards the northeast.

"The army was concentrated around Al-Qaryatain, and today (Monday) the military operations began there," a military source in Palmyra told AFP.

"That is the next goal for the Syrian army. They also have their eyes on Sukhnah."

The head of the Syrian Observatory for Human Rights, Rami Abdel Rahman, said the capture of Sukhnah would bring government forces to the gates of oil-rich Deir Ezzor province, an ISIS bastion.

ISIS overran Palmyra - a UNESCO world heritage site known as the "Pearl of the Desert" - in May 2015 and used its ancient amphitheater for public executions as the world watched in horror.

The extremist group blew up temples and tower tombs, as part of it campaign against pre-Islamic monuments it considers "blasphemous."

An AFP correspondent in Palmyra saw the Temple of Bel and the Arch of Triumph in pieces on Sunday, with some large stones marred by spray painted messages in support of ISIS.

"Five years" to restore

On Monday, army sappers continued to defuse roadside bombs and mines that ISIS had planted in the ancient city as it retreated.

One soldier said more than 50 bombs had already been defused as other units worked on the controlled detonation of more complex devices.

Antiquities chief Abdulkarim said his department would need five years to restore the Temple of Bel and other monuments destroyed by ISIS.

"If we have UNESCO's approval, we will need five years to restore the structures damaged or destroyed by ISIS," he told AFP.

He said "several experts" had arrived in Palmyra on Monday to assess the damage, but that a preliminary assessment showed 80% of the ancient site was "in good shape."

The famed Lion of Al-Lat, shattered by ISIS last year outside the city's museum, could be put back together and there was not the widespread looting that had been feared, he said.

"We need to start with the damage in the citadel immediately, because it can't afford all the damage that it has suffered."

"Undeniable loss" for ISIS

As government troops made their final push on Sunday, ISIS terrorists fled to Sukhnah and to Deir Ezzor in the Euphrates valley further east.

The US-based Soufan Group said ISIS "suffered an undeniable loss" with its defeat in Palmyra.

The jihadist organization has come under growing pressure from Syrian and Iraqi forces set on breaking apart its self-proclaimed "caliphate."

The group has been responsible for a spate of deadly attacks abroad, most recently in Brussels, where 35 people were murdered last week.

"The past week exemplifies the future of the Islamic State: relentless internal setbacks amid persistent external attacks," the Soufan Group said in a briefing paper.

"While the group maintains the ability to seize minor towns in both Iraq and Syria, it is facing a larger tactical defeat."

Long keen to portray his army as the vanguard of the fight against the jihadists, Assad hailed Sunday's victory in Palmyra as an "important achievement."

Russian President Vladimir Putin, whose government provided both air and ground support for the offensive, congratulated Damascus on its success.

Assad's other key ally, Iran, hailed the victory and pledged its continued financial and military assistance.

The Syrian army has vowed to build on its recapture of Palmyra with assaults on other ISIS-held towns, including the jihadists' de facto Syrian capital Raqa to the north.

A second government fighter in Palmyra told AFP the army's immediate concern was "securing the area around Palmyra specifically, and eastern parts of Homs province in general."

Then, government forces would concentrate on "clearing the (ISIS) fighters that fled from Palmyra to nearby areas."

Finally, they would aim to "find out what happened to the families that were in Palmyra... We're afraid they've been kidnapped."

Some 15,000 of Palmyra's 70,000 residents had stayed on under ISIS rule.

The residential area of the city saw heavy fighting between government forces and ISIS. Most apartment blocks bore marks of the fighting and several had completely collapsed, the AFP correspondent reported.

AFP contributed to this report.