Islamic State continued its destruction of Iraqi historical and cultural sites as it attacked the ancient city of Hatra in northern Iraq on Saturday.

Hatra is 110 kilometers (70 miles) south of Mosul, which is held by Islamic State. It was declared a World Heritage Site in 1987 by UNESCO. Its history stretches back 2,000 years, and one of its most important cultural sites is a large pillared temple located within a site of archaeological significance.

According to an article in the Daily Star, the Iraqi Tourism and Antiquities Ministry said that its employees witnessed Islamic State fighters demolishing the ancient structures in the city on Saturday.

While the Ministry did not confirm the report, the Kurdish Democratic Party spokesman in Mosul, Saeed Mamuzini, said that the militants were blowing up larger buildings in the city using explosives, while bulldozing the rest.

In response, the Antiquities Ministry lamented the lack of international response to the series of Islamic State attacks on Iraqi cultural sites, and said that this is further encouraging the group to continue destroying places of historical and cultural importance in the country.

"The delay in international support for Iraq has encouraged terrorists to commit another crime of stealing and demolishing the remains of the city of Hatra," the Ministry's statement said.

The demolition of the ancient structures in Hatra followed the Islamic State's attack on the Assyrian city of Nimrud on Thursday. In Nimrud, the ISIS militants destroyed ancient works in its museum, and bulldozed the remains of the city's ruins.

UNESCO condemned the assault on Nimrud and called the destruction of cultural relics "war crimes." The artefacts in Nimrud are said to be more than 3,000 years old.

In July, the militants also destroyed the biblical city of Nineveh, where the tomb of the prophet Jonah is located.