BEIRUT — The destruction of the nearly 2,000-year-old temple of Baalshamin by Islamic State militants erased a symbol of the once rich religious life of Syria's ancient caravan city of Palmyra and left residents, archaeologists and historians fearful that the extremists will destroy more of the rich site, including an even larger more ancient temple nearby.
The U.N. cultural agency UNESCO on Monday called the destruction of the temple a war crime. For archaeologists, it deepened their despair and frustration over the systematic destruction of Syria's heritage in the country's civil war, not only by the extremists but by government forces, who have bombed and looted historic sites since the conflict began in 2011.
No pictures have yet emerged of the extent of the destruction of the temple. One resident told The Associated Press he saw it after it was blown up Sunday and said it was reduced to "rocks on the ground, nothing more."
The witness, who goes by the name Nasser al-Thaer, said the bombing took place Sunday shortly after 4pm. The militants had lined the inner and outer walls of the temple with bottles of explosives more than a month ago, he said.
"I went to see it, not from very close because IS (militants) were there and because I was worried for myself and afraid they will ask me what are you doing here. So I saw it from a distance," al-Thaer told the AP.
He said he feared other ancient sites in Palmyra might be next, though so far no explosives have been placed around them.
An IS operative confirmed the temple was destroyed and said a statement would be issued soon. He spoke to the AP over Skype on condition of anonymity because members of the group are not allowed to speak to media.
The temple, a structure of giant stone blocks several stories high fronted by six towering columns, was dedicated to a god of storm and rain — the name means literally "Lord of the Heavens" — part of a sprawling Roman-era complex that includes other remains of temples to local gods and goddesses, including the even larger and slightly older Temple of Bel.
In ancient times, the city grew rich sitting on caravan routes crossing east and west, eventually coming under Roman rule. In the modern day, it is one of the best preserved ancient cities in the world and among the most popular tourist sites in the Middle East.
The Islamic State group, which has imposed a violent interpretation of Islamic law across its self-declared caliphate straddling Syria and Iraq, says such ancient relics promote idolatry. It has already blown up several sites in neighboring Iraq, and it is also believed to sell looted antiquities. The group had seized control of Palmyra, in the central deserts of Syria, in May.
Kishore Rao, Director of the UNESCO World Heritage Centre, said Palmyra's soaring architecture was a "masterpiece of human creative genius."
"The destruction of any part of it is equally deplorable," Rao told The Associated Press. Rao said while efforts to stop the looting and selling on the black market have been launched, it was difficult to stop the destruction.
"We don't have people on the ground who can prevent that," he said. "Very difficult to prevent unless you appeal to the consciousness of these people, and the international community needs to come together and speak with one voice," he said.
Amr Al-Azm, a former Syrian government antiquities official and now a professor in Shawnee State University in Ohio, said Baalshamin is the most significant site destroyed by the group inside Syria.
IS has used the ancient city has cover to avoid airstrikes from the international coalition against its locations, he said. It also used its Roman amphitheater as a stage when it killed 20 captured Syrian soldiers.
The ruins, located on the outskirts of the modern city of Palmyra, had already been badly damaged by government troops during fighting in the area since the start of the conflict.
Satellite imagery has shown that new roads, flanked by earthen berms, were cut through the center of northern part of the archaeological site, an area that was used by military vehicles. According to a recently published study archaeologist Cheikhmous Ali of France's University of Strasbourg, the Baalshamin temple was damaged in fighting since 2012, causing part of frieze on its portico and the top of a column to collapse.
Another achaeologist Martin Makinson, who lived and worked in Syria until 2011, compared the temple's destruction to the Islamic State's destruction earlier this year of the Hatra, a 2,000-year-old trading city in Iraq. "It was the Palmyra of Iraq," he said in an interview from Paris.
The foundation of the Temple of Baalshamin dates back to 23 A.D., though most the structure that was destroyed Sunday dated back to 130 A.D. and was built and embellished by a rich resident of the city, said Makinson, a member of the Association for the Protection of Syrian Archaeology, which documents the looting and destruction of historic sites.
The temple was "one of the most alluring" sites at Palmyra, and was "particularly well preserved," said Maurice Sartre, an emeritus professor of archaeology at the University of Tours, France. "It was enjoyable to look at. It's a small temple, and did a lot for the overall charm of Palymra."
Sartre's wife, Anne Sartre Fauriat, who co-authored a book with him on Palmyra, said Palmyra's temples "are the symbol and testimony of the religious life of the city, the oasis. Baalshamin was one of the most important gods of the city," she said.
But several of the archaeologists pointed to the wider failures to protect Syria's antiquities — and people. They noted damage to sites by government forces has largely gone with little condemnation, including last year's damage to the 900- year-old Crac de Chevaliers, one of the world's best preserved medieval crusader castles. Government airstrikes and shelling damaged its roof and walls.
"Of course, I am worried (about other sites) but I am also very, very angry because for four years now nobody has done anything for Syrian people, for Syrian sites," said Fauriat, a longtime French Palmyra expert and Greco-Roman historian.
Associated Press Writer Jamey Keaten, Maggy Donaldson, Jeff Schaeffer and Alex Turnbull contributed to this report from Paris.