The Syrian Observatory for Human Rights (SOHR), an activist group monitoring the war in Syria through on ground sources, said on Sunday that ISIS has planted mines and bombs in the ancient city of Palmyra.
Palmyra is home to Roman-era ruins and is a 2,000-years-old antique city, which was added to the UNESCO World Cultural Heritage List in 1980.
The SOHR said “it was not immediately clear whether the group was preparing to destroy the ancient ruins or planted the mines to deter government forces from advancing towards the city.”
Rami Abdulrahman, the head of the Observatory, told Reuters that "They have planted [the bombs] yesterday. They also planted some around the Roman theater, we still do not know the real reason."
Maamoun Abdulkarim, Syria's head of antiquities, told Reuters that the reports of ISIS planting mines in Palmyra "seems true."
"The city is a hostage in their hands, the situation is dangerous."
ISIS seized the ancient city of Palmyra in May as Syrian regime troops withdrew from the region after fierce fighting with the militants.
Palmyra has a significant and strategic location in the middle of Syria as it links the capital Damascus with the northeastern part of the county where the ISIS militants have been operating since last year.
Syria's antiquities chief Maamoun Abdul Karim previously called the US-led coalition forces to save Palmyra’s ancient ruins and monuments from the militants’ destruction, which seems very likely since the group has already destroyed similar archaeological sites and museums in Iraq.
“Regime forces were seen carrying a number of monumental artifacts while withdrawing from a security point in the southern part of the city,” Khaled al-Homsi, a member of Tadmur’s media coordination team told reporters last month.
ISIS militants had smashed the ruins of Assyrian city of Nimrud and artifacts in the Mosul Museum earlier this year, a move that sparked the outrage of international community.
ISIS captured the Syrian Province of Raqqa, declaring it the capital of their self-proclaimed “caliphate” in June 2014 after seizing swathes of territory in Syria and Iraq.
A US-led coalition started air strikes in Syria and Iraq against ISIS targets last September.
The war in Syria started in 2011 in the form of anti-government demonstrations, but descended into a civil war between five main fronts - the regime, the opposition, Al Qaeda affiliate Nusra Front, ISIS, and the Kurdish YPG militia.
Over four years of fighting has left over 230,000 Syrians dead, according to UN estimates.
More than 6.7 million are displaced internally while at least 5 million have fled the country to the neighbouring countries of Turkey, Lebanon, Egypt and Jordan.