Palmyra (Syria) (AFP)

Syrian troops recaptured the ancient city of Palmyra from the Islamic State group on Sunday and pledged to build on the win with an advance against other jihadist strongholds.

The army said pro-government forces had cleared IS fighters from the UNESCO world heritage site, where the jihadists sparked a global outcry with the systematic destruction of treasured monuments.

“Palmyra will be the central base to broaden operations… against Daesh in numerous areas, primarily Deir Ezzor and Raqa,” the armed forces said in a statement carried by state media, using an Arabic name for IS.

The northern city of Raqa is IS’s main Syrian bastion and the oil-rich eastern province of Deir Ezzor is another key stronghold.

Backed by a barrage of Russian air strikes, Syrian troops and allied militia launched a major offensive to retake the desert city this month.

Palmyra is both an important symbolic and strategic prize for President Bashar al-Assad’s forces, as it provides control of the surrounding desert extending all the way to the Iraqi border.

At least 400 IS fighters were killed in the battle for the city, the Syrian Observatory for Human Rights said. On the government side, 188 troops and militiamen were killed.

“That’s the heaviest losses that IS has sustained in a single battle since its creation” in 2013, the director of the Britain-based monitoring group, Rami Abdel Rahman, told AFP.

– Jihadists under pressure –

A military source told AFP that IS militants had retreated towards the east as the army made its final push.

The Observatory said the pullout had been ordered by IS high command.

“A handful of IS fighters are refusing to leave the city and seem to want to fight on to the bitter end,” Abdel Rahman said.

After the army took control of the city, sappers were defusing mines and bombs planted by IS in the ancient ruins, the source said.

Syrian state television broadcast footage from inside the famed Palmyra museum, where jagged pieces of sculptures lay blanketed in dust on the ground. A stone head of an unidentified statue lay in the centre of one room, surrounded by cracked columns.

Most of the pieces in the city’s museum were evacuated by antiquities staff before IS arrived in May 2015, but larger artefacts that could not be moved remained in the building.

Outside, in the city’s main roundabout, a small group of army soldiers strolled through debris-covered streets under a clear sky.

IS, behind a string of attacks in the West including last week’s Brussels bombings, is under growing pressure from Syrian and Iraqi military offensives to retake bastions of its self-proclaimed “caliphate”.

On Thursday, the Iraqi army announced the launch of an offensive to eventually recapture second city Mosul, held by the jihadists since June 2014.

IS overran the Palmyra ruins and adjacent modern city in May 2015. The group blew up two of the site’s treasured temples, its triumphal arch and a dozen tower tombs, in a campaign of destruction that UNESCO described as a war crime.

– Boost to ‘confidence and morale’ –

The jihadists used Palmyra’s ancient theatre as a venue for public executions and also murdered the city’s 82-year-old former antiquities chief.

UNESCO chief Irina Bokova on Thursday welcomed the Syrian government offensive to recapture the city.

“Palmyra has been a symbol of the cultural cleansing plaguing the Middle East,” she said.

Russian forces, which intervened in support of longtime ally Assad last September, were heavily involved in the Palmyra offensive despite a major drawdown last week.

Russian warplanes conducted more than 40 combat sorties in just 24 hours from Friday to Saturday, targeting “158 terrorist” positions, according to the Russian defence ministry.

IS and its jihadist rival, the Al-Qaeda-affiliated Al-Nusra Front, are not party to a landmark ceasefire in Syria since February 27.

Fighting has largely stopped in many areas across Syria, but government forces appeared ready to take the fight against IS further.

By defeating IS in Palmyra, “the army will have regained confidence and morale, and will have prepared itself for the next expected battle in Raqa,” a military source said on Saturday.

Palmyra was a major centre of the ancient world as it lay on the caravan route linking the Roman Empire with Persia and the east.

Pledging Russian support for the offensive to retake the city earlier this month, President Vladimir Putin described it as a “pearl of world civilisation”.

Situated about 210 kilometres (130 miles) northeast of Damascus, it drew some 150,000 tourists a year before it became engulfed by Syria’s civil war, which has killed more than 270,000 people and forced millions from their homes in the last five years.