Two of Syria's most iconic structures have fallen down because of the Islamic State militants. The Russian Ministry of Defense has released a drone footage last week showing the damage at the ancient Roman-era site of Palmyra.
Reports from Associated Press said the video showed the destruction brought upon by the group in the Roman-era theater and the Tetrapylon -- a set of four monuments with four columns each at the center of the colonnaded road leading to the theater.
The video showed the theater in ruins and the Tetrapylon with only four columns left standing.
Live Science reported that according to the Syrian Observatory for Human Rights, the militants are again using the archaeological site for mass executions, killing a group of 12 prisoners on Jan. 19.
"One might interpret these destructions and the recent executions of prisoners, including civilians, at Palmyra as designed by Daesh to develop propaganda," said Michael Danti, a Boston University archaeologist and academic director of ASOR CHI, as quoted by the website.
Aside from destroying the UNESCO heritage sites, they also destroyed 180 "infrastructure objects" and 15 ammunition depots.
The Russian Ministry of Defense said the militants are planning more demolitions as they advance to claim the ancient city.
CBS News cites that ISIS seized the town again in December after the Russian and Syrian government had driven them away in April 2016. During the time when the ISIS occupied the land, antiquities and ancient temples were destroyed and most of the residents were killed.
UNESCO Director-General Irina Bokova referred to ISIS' actions as a "new war crime" on Syria and for humanity.
"This new blow against cultural heritage, just a few hours after UNESCO received reports about mass executions in the theater, shows that cultural cleansing led by violent extremists is seeking to destroy both human lives and historical monuments in order to deprive the Syrian people of its past and its future," Bokova said in a statement.