While ISIS hasn't yet destroyed the UNESCO world heritage site of Palmyra is captured in May, it has now planted mines and bombs in the ancient part of the central Syrian city, amid the Roman-era ruins according to a group monitoring the war.
On Sunday The Syrian Observatory for Human Rights said it was unclear whether the terror group was preparing to destroy the ancient ruins or had planted the explosives to deter government forces from advancing on the city.
"They have planted it yesterday. They also planted some around the Roman theater, we still do not know the real reason," said Rami Abdulrahman, head of the Observatory
Maamoun Abdulkarim, Syria's head of antiquities, confirmed the reports, saying the accounts "seemed true."
"The city is a hostage in their hands, the situation is dangerous."
The radical Islamic group seized the city of 50,000 people and home of some of the world's most best-preserved ancient Roman ruins in May.
The Islamic State has created a self-styled stat in Syria and Iraq, where it rules residents with strict Islamic law backed by sexual violence and death.
Its militants have a history of carrying out mass killings and rapes in the towns and cities they capture. They've also destroyed ancient monuments which they consider to be evidence of paganism.