BAGHDAD — Extremist Islamist militants in northern Iraq have destroyed a priceless collection of statues and sculptures from the ancient Assyrian era, inflicting what an archaeologist described as incalculable damage to a piece of shared human history.

A video published by “Islamic State” on Thursday showed men attacking the artifacts, some of them identified as antiquities from the 7th century BCE, with sledgehammers and drills, saying they were symbols of idolatry.

“The Prophet ordered us to get rid of statues and relics and his companions did the same when they conquered countries after him,” an unidentified man said in the video.

The smashed articles appeared to come from an antiquities museum in Mosul, the northern city which was overrun by IS last June, a former employee at the museum told Reuters.

The militants shoved stone statues off their plinths, shattering them on the floor, and one man applied an electric drill to a large winged bull. The video showed a large exhibition room strewn with dismembered statues, and Islamic songs played in the background.

Lamia al-Gailani, an Iraqi archaeologist and associate fellow at the London-based Institute of Archaeology, said the militants had wreaked untold damage. “It’s not only Iraq’s heritage: it’s the whole world’s,” she said.

“They are priceless, unique. It’s unbelievable. I don’t want to be Iraqi any more,” she said, comparing the episode to the dynamiting of the Bamiyan Buddhas by the Afghan Taliban in 2001.

As well as Assyrian statues of winged bulls from the Mesopotamian cities of Nineveh and Nimrud, Gailani said the “Islamic State” hardliners appeared to have destroyed statues from Hatra, a Hellenistic-Parthian city in northern Iraq dating back around 2,000 years.

Eleanor Robson, professor of Ancient Near Eastern History at University College London, also said on Twitter that statues from Hatra and Nineveh had been wrecked, though she added that some objects shown in the video were modern replicas.

The director of UNESCO’s Iraq office, Axel Plathe, would not comment on the content of the video, saying it has yet to be verified. But he described the damage to Iraq’s heritage since “Islamic State” overran Mosul last year as an attempt “to destroy the identity of an entire people”.

Plathe said UNESCO was working with Iraqi authorities and governments of neighboring countries to crack down on the smuggling of artifacts from areas under IS control and had alerted auction houses to be on the lookout for stolen items.

IS fighters have also destroyed Shi’a and Sufi religious sites and attacked churches and other shrines in the parts of Syria and Iraq under their control.

“Muslims, these relics you see behind me are idols that were worshipped other than God in the past centuries,” the unidentified man in the IS video said.

“What is known as Assyrians, Akkadians and others used to worship gods of rain, farming and war other than God and pay all sorts of tributes to them.”

Last week, IS released another video showing a pile of books in flames.

An employee of the Mosul museum said he feared these books were manuscripts from the library of endowments, although the library itself was still intact last week.