A day after ISIS militants in Iraq destroyed the remains of the ancient Assyrian city of Nimrud, fighters from the Islamist group have begun looting the ancient city of Hatra, the Associated Press reports.

Saeed Mamuzini, a Kurdish official from Mosul, told the AP that members of ISIS had begun pillaging the city on Thursday. A tourism official said that multiple residents living near Hatra heard two large explosions on Saturday morning and reported seeing bulldozers demolishing the site.

"The destruction of Hatra marks a turning point in the appalling strategy of cultural cleansing underway in Iraq," a joint statement from Irina Bokova, Director-General of UNESCO, and Dr. Abdulaziz Othman Altwaijri, Director General of the Islamic Educational, Scientific and Cultural Organization (ISESCO), reads. "This is a direct attack against the history of Islamic Arab cities, and it confirms the role of destruction of heritage in the propaganda of extremists groups."

On the history of Hatra, from the AP:

Hatra, located 110 kilometers (68 miles) southwest of the city of Mosul, was a large fortified city during the Parthian Empire and capital of the first Arab kingdom. A UNESCO world heritage site, Hatra is said to have withstood invasions by the Romans in A.D. 116 and 198 thanks to its high, thick walls reinforced by towers. The ancient trading center spanned 6 kilometers (4 miles) in circumference and was supported by more than 160 towers. At its heart are a series of temples with a grand temple at the center — a structure supported by columns that once rose to 100 feet.

"The deliberate destruction of cultural heritage constitutes a war crime," Bokova said in a statement on Friday condemning the bulldozing of Nimrud. "I call on all of those who can, especially youth, in Iraq and elsewhere, to do everything possible to protect this heritage, to claim it as their own, and as the heritage of the whole of humanity."

[Photo credit: AP Images]