Forces loyal to Syria’s President Bashar al-Assad stand near a road sign that shows the direction to the historic city of Palmyra in this picture provided on March 24, 2016.

Aided by Russian strikes, Syrian government forces on Thursday entered the historic city of Palmyra, which has been held by ISIS since May.

Troops reached the “heart” of Palmyra, the state-run Ikhbariya news channel reported, broadcasting images from just outside the historic city which has been held by ISIS since May last year.

A soldier interviewed by Ikhbariya said the army and its allies would press forward beyond Palmyra.

“We say to those gunmen, we are advancing to Palmyra, and to what’s beyond Palmyra, and God willing to Raqqa, the center of the Daesh gangs,” he said, referring to ISIS’s de facto capital in northern Syria.

The state news agency SANA showed warplanes flying overhead, helicopters firing missiles, and soldiers and armored vehicles approaching Palmyra.

Earlier, ISIS militants called on the 15,000 or so civilians still living in Palmyra to leave the city on Thursday.

“IS called on loudspeakers on civilians still in Palmyra to leave as fighting reached the outskirts of the city,” the Syrian Observatory for Human Rights said, using another acronym for the militants.

Russian help

Russia’s Defense Ministry says its warplanes had struck targets around the ancient city of Palmyra in support of the Syrian army’s offensive.

The ministry said Russian warplanes hit 146 targets Sunday through Wednesday, killing 320 militants. It said in Thursday’s statement that Russian jets also destroyed five tanks, six artillery systems, two ammunition depots and 15 vehicles.

President Vladimir Putin last week ordered a pullout of some Russian warplanes from Syria, but said that strikes against ISIS and the al-Qaeda-linked Nusra Front will continue.

Recapturing the town, a UNESCO world heritage site, would be a significant victory for the army and its Russian allies. Russia withdrew most of its forces and aircraft from Syria last week after a months-long bombing campaign that succeeded in turning the tide of the war again in President Bashar Assad’s favor.

The Britain-based Syrian Observatory for Human Rights said that Syrian troops and Shiite militiamen helping them on the ground were facing tough resistance from ISIS extremists as they try to penetrate the town’s limits.

The group, which monitors the Syrian conflict through a network of activists on the ground, said the ISIS lost over 200 militants since the government campaign to retake Palmyra began 17 days ago. The Observatory did not have figures for government losses.

Palmyra attracted tens of thousands of tourists to Syria every year and is affectionately known by Syrians as the “bride of the desert.”

In Palmyra, ISIS destroyed many of the town’s Roman-era relics, including the 2,000-year-old Temple of Bel and the iconic Arch of Triumph, and also killed dozens of captive Syrian soldiers and dissidents from IS in public slayings at the town’s grand roman theater and other ruins.

Along with blowing up priceless archaeological treasures, among the first destructions ISIS carried out in Palmyra was the demolishing of the town’s infamous Tadmur prison, where thousands of Syrian government opponents had been imprisoned and tortured over the years.

The advance on Palmyra comes against the backdrop of Syrian peace talks underway in Geneva between representative of the Damascus government and the Western-backed opposition. The talks, which have been boosted by a Russia-U.S.-brokered cease-fire that has mostly held since late February, were to adjourn on Thursday – without having achieved any apparent breakthroughs.

UNESCO chief Irinia Bokova on Thursday welcomed the push to recapture Palmyra.

“For one year, Palmyra has been a symbol of the cultural cleansing plaguing the Middle East,” the head of the UN’s cultural body said, adding that she welcomed the effort to retake “the Palmyra archaeological site, martyr city inscribed on the UNESCO world heritage list.”

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