BEIRUT - Islamic State group militants have laid landmines and explosives at the site of the ancient ruins in Syria's Palmyra, a monitor said Sunday, adding the purpose of the move was unclear.
The head of Syria's antiquities department, reached by phone in Damascus, said he had also received reports from Palmyra residents that mines were laid at the site.
The Syrian Observatory for Human Rights, which relies on a network of sources on the ground, said explosives were laid at the ruins in the town in central Homs province on Saturday.
"But it is not known if the purpose is to blow up the ruins or to prevent regime forces from advancing into the town," said Observatory director Rami Abdel Rahman.
He said regime forces had launched heavy air strikes against the residential part of Palmyra in the past three days, killing at least 11 people.
"The regime forces are to the west outside the city, and in recent days they have brought in reinforcements suggesting they may be planning an operation to retake Palmyra," he added.
IS fighters captured Palmyra, which is famed for its extensive and well-preserved Greco-Roman ruins, on May 21.
The city's fall prompted fears the extremist group would seek to destroy the UNESCO World Heritage listed ruins as they have done with heritage sites elsewhere in Syria and Iraq.
So far there have been no reports of IS damage to the ruins or antiquities there, though the group did reportedly enter the city's museum, which was largely emptied of its collection before the jihadists arrived.
Syrian antiquities chief Maamoun Abdulkarim said Sunday he had received reports from Palmyra residents that the ruins had been mined.
"We have preliminary information from residents saying that this is correct, they have laid mines at the temple site," he told AFP.
"I hope that these reports are not correct, but we are worried." He urged "Palmyra's residents, tribal chiefs and religious and cultural figures to intervene to prevent this... and prevent what happened in northern Iraq," referring to IS's destruction of heritage sites there.
"I am very pessimistic and feel sadness," he added.
IS has released several videos documenting its destruction of heritage sites in Iraq and Syria.
In the jihadists' extreme interpretation of Islam, statues, idols and shrines amount to recognising objects of worship other than God and must be destroyed.
The extremist group controls large sections of Iraq and Syria, territory it refers to as its Islamic "caliphate."