The Islamic State in Iraq and Syria (ISIS) seized portions of Syria’s historic Palmyra ruins Saturday.
ISIS forces now occupy the ancient city’s northern quarter, BuzzFeed reported.
Britain’s Syrian Observatory for Human Rights added in a statement that 13 ISIS soldiers died in fighting for the cultural site.
{mosads}The terrorist organization clashed with Syrian troops over an old Islamic citadel, it added.
ISIS’s victory in Palmyra – also called Tadmur – raises fears about preserving the city’s cultural significance.
The group has previously destroyed priceless religious artifacts in territory it has conquered in Iraq and Syria.
The United Nations Educational, Scientific and Cultural Organization (UNESCO) lists Palmyra as a world heritage site.
“We must save Palmyra,” said UNESCO Director-General Irina Bokova in a statement from Paris on Thursday.
“This site has already suffered four years of conflict,” she said, referencing the civil war between Syrian rebels and Syrian President Bashar al-Assad.
“It suffered from looting and represents an irreplaceable treasure for the Syrian people and the world,” Bokova said. “I appeal to all parties to protect Palmyra and make every effort to prevent its destruction.”
UNESCO’s website lists Palmyra as “one of the most important cultural centres of the ancient world.”
The desert oasis was established in the 1st century AD.
Palmyra’s central location in the Middle East made it a hub of cultural exchange between the ancient Persians and Romans.
ISIS’ victory there Saturday was tempered by a crushing defeat elsewhere in Syria the same day.
A U.S. Special Forces raid on the group earlier that morning killed senior ISIS leader Abu Sayyaf.
Secretary of Defense Ash Carter praised the mission as a major victory in the fight against the radical Islamists.
“The operation represents another significant blow to ISIL, and it is a reminder that the United States will never waver in denying safe haven to terrorists who threaten our citizens, and those of our friends and allies,” he said, using an alternate acronym for the group.
Sayyaf reportedly helped control ISIS’s oil and gas resources.
American forces killed the terrorist when he “engaged U.S. forces” rather than risk capture.
U.S. soldiers also apprehended Sayyaf’s wife, Umm Sayyaf, and freed a young Yezidi woman who was reportedly the couple’s slave.