DAMASCUS, Syria -- Islamic State fighters broke into the museum of Palmyra, though a Syrian official said its artifacts have been removed and are safe, while the U.S.-led coalition conducted airstrikes on the group's installations near the captured ancient town -- the first such attack reported in the central province of Homs.
The Department of Defense said in a statement that U.S.-led coalition aircraft had attacked an Islamic State position near Palmyra, which goes by the modern name Tadmur, destroying six anti-aircraft artillery systems and an artillery piece.
The Islamic State extremist group captured Palmyra on Wednesday, raising concerns around the world that they would destroy priceless, 2,000-year-old temples, tombs and colonnades located in the town's south.
The strikes would appear to help the embattled forces of forces of President Bashar Assad, which have had a succession of recent defeats to the Islamic State and other rebels. But experts and archaeologists said the airstrike, coming days after the group overwhelmed the city, was too little too late.
"It is like closing the doors after the horses have bolted," said Amr Al-Azm, a former Syrian antiquities official and currently a professor at Shawnee State University in Ohio.
The extremist group says the ancient relics promote idolatry, but it also maintains a lucrative business excavating and selling such artifacts on the black market, according to antiquities authorities.
Maamoun Abdulkarim, the head of the Antiquities and Museums Department in Damascus, said militants entered the museum in the town's center Friday afternoon. He said that the artifacts earlier had been moved away to safety.
"We feel proud as all the museum's contents were taken to safe areas," he said.
Al-Azm said he doubts the museum was totally emptied because larger pieces would be hard to move. He said the museum also contained at least two mummies and carvings from the nearby tombs, mostly dating to the first, second and early third century.
So far, the militants have been primarily concerned with consolidating their control over the city, conducting house-to-house searches for government soldiers and pro-government militiamen and, in some cases, publicly killing those that they find, according to activists and government officials.
The Defense Department statement didn't specify where the strikes took place. Activists said they heard of no airstrikes in the immediate vicinity of the town, but that the battles between Islamic State fighters and government forces have continued in a mountainous area containing oil fields northwest of the town.
Meanwhile, the Islamic State claimed responsibility Saturday for a suicide bombing at a Shiite mosque in Saudi Arabia, warning that more "black days" loom ahead in a challenge to the rulers of the Sunni kingdom.
The statement on the Islamic State's al-Bayan radio station, posted Saturday morning to militant websites associated with the extremists, identified the suicide bomber as a Saudi citizen with the nom de guerre Abu Amer al-Najdi. The station also identified the attack as being carried out by a new Islamic State branch in "Najd province," referring to the historic region of the central Arabian Peninsula that is home to the Saudi capital, Riyadh.
The mosque attack Friday killed at least 21 people and wounded 81, the official Saudi Press Agency reported.
The Islamic State holds a large stretch of territory across Syria and neighboring Iraq. In Iraq, police Col. Aziz al-Shihawi said that Iraqi troops and Shiite militias recaptured the town of Husseiba in Anbar province Saturday.
In Washington, U.S. defense officials said Iran has entered the fight to retake a major Iraqi oil refinery from Islamic State militants, contributing small numbers of troops -- some are operating artillery and other heavy weapons -- in support of advancing Iraqi ground forces.
Two U.S. defense officials said Iranian forces have taken a significant offensive role in the Beiji operation in recent days, in conjunction with Iraqi Shiite militias. The officials were not authorized to discuss the matter publicly and spoke Friday on condition of anonymity.
The Iranian role was not mentioned in a new U.S. military statement asserting that Iraqi security forces, with U.S. help, had managed to establish a land route into the Beiji refinery compound.
On Saturday, the commander of international forces in Afghanistan said the Islamic State is actively recruiting in Afghanistan but is not yet operational there.
Gen. John Campbell said the group's social-media campaign was attracting Taliban fighters based in Afghanistan and Pakistan who are disgruntled with the lack of progress in more than 10 years of fighting to overthrow the Kabul government.
He said Afghans largely did not agree with the ideology of the Islamic State. But he contradicted his earlier statement that the Islamic State was not active on the battlefields of Afghanistan by saying it was reportedly fighting the Taliban for control of territory and men.
Information for this article was contributed by Sameer N. Yacoub, Maamoun Youssef, Lynne O'Donnell, Robert Burns and Rahim Faiez of The Associated Press.
A Section on 05/24/2015