Syrian army units were clearing land mines and explosives left behind by Islamic State militants in the historic town of Palmyra on Friday, a day after government troops and allied militiamen recaptured it from the extremists, a Syrian security official said.
The military expects the process to be long and difficult due to the large number of mines planted by IS, he said, speaking on condition of anonymity in line with regulations.
Syrian troops fully recaptured Palmyra on Thursday after a push that saw the militants' defenses crumble and IS fighters flee in the face of artillery fire and intense Russia-backed airstrikes.
It's the third time the town — famed for its priceless Roman ruins and archaeological treasures IS had sought to destroy — has changed hands in one year. The Syrian government seized the town from Islamic State militants last March, only to lose it again 10 months later.
Last spring, it took Russian demining experts weeks to clear the town from hundreds of mines planted by IS. .
Before the civil war gripped Syria in 2011, Palmyra was a top tourist attraction, drawing tens of thousands of visitors each year.
Syrian state television broadcast footage showing troops near the town's archaeological site, a UNESCO World Heritage Site, and the historic citadel on Friday.
Archeologists have decried what they say is extensive damage to Palmyra's treasured ruins.
Drone footage released by Russia's Defense Ministry last month showed new damage IS had inflicted to the facade of Palmyra's Roman-era theater and the adjoining Tetrapylon — a set of four monuments with four columns each at the center of the colonnaded road leading to the theater.
The Islamic State group has destroyed scores of ancient sites across its self-styled Islamic caliphate in Syria and Iraq, viewing them as monuments to idolatry.
Maamoun Abdu-Karim, the head of the Antiquities and Museums Department in Syria, told The Associated Press on Thursday night that this time around, the damage to the ruins seemed less in magnitude.
"We had expected the worst. However, the damage, according to the available photos, appears limited," he said.
But the Islamic State group is not the only side in Syria's civil war, now in its sixth year, that has damaged Palmyra.
A 2014 report by a U.N. research agency disclosed satellite evidence of looting while the ruins were under Syrian military control. Opposition fighters have also admitted to looting the antiquities for funds.