Islamic State militants hammered, bulldozed and ultimately blew up parts of the ancient Iraqi Assyrian city of Nimrud, destroying a site dating back to the 13th century B.C., an online militant video purportedly shows.

The destruction at Nimrud, located near the militant-held city of Mosul, follows other attacks on antiquity carried out by the group now holding a third of Iraq and neighboring Syria in its self-declared caliphate.

The attacks have horrified archaeologists and U.N. Secretary-General Ban Ki-moon, who last month called the destruction at Nimrud ‘a war crime.’

The seven-minute video, posted late Saturday, shows bearded militants using sledgehammers, jackhammers and saws to take down huge alabaster reliefs depicting Assyrian kings and deities.

A bulldozer brings down walls, while militants fill barrels with explosives and later destroy three separate areas of the site in massive explosions.

‘God has honored us in the Islamic State to remove all of these idols and statutes worshipped instead of Allah in the past days,’ one militant says in the video. Another militant vows that ‘whenever we seize a piece of land, we will remove signs of idolatry and spread monotheism.’

The militants have been destroying ancient relics they say promote idolatry that violate their fundamentalist interpretation of Islamic law, including the ancient Iraqi city of Hatra, a UNESCO World Heritage site. Authorities also believe they’ve sold others on the black market to fund their atrocities.

Some of the figures in the video released Saturday at Nimrud appeared to have rebar, ribbed bars of steels designed to reinforce concrete that are a technique of modern building.

An Iraqi Antiquities Ministry official, speaking Sunday on condition of anonymity as he wasn’t authorized to talk to journalists, said all the items at Nimrud were authentic.

In March, both Iraqi and United Nations officials warned the site had been looted and damaged.

The video conformed to other Associated Press reporting about the militants’ attack.

This is only the most recent video showing Islamic State fighters destroying invaluable heritage sites.

A shocking video emerged last week, showing ISIS militants using sledgehammers and AK-47 rifles to destroy walls and statues in Iraq’s UNESCO World Heritage city of Hatra.

In the slickly produced seven minute footage, jihadists are shown smashing shrines and statues in the 2,000-year old city.

Militants are also recorded chipping away at the bases of some of the larger wall sculptures and cracking boulders into ancient city pillars, while eerie music plays in the background.

The video cuts to jihadists speaking directly to the camera with one declaring they destroyed the site because it is ‘worshipped instead of God’.

Last month, ISIS terrorists were pictured toppling crosses, smashing Christian relics with hammers and erecting the black flag of ISIS on churches in Nineveh, the ancient capital of the Assyrian empire.